diff --git a/src/img/img/gsiDeclImg.cc b/src/img/img/gsiDeclImg.cc
index 27e13f72c..096375845 100644
--- a/src/img/img/gsiDeclImg.cc
+++ b/src/img/img/gsiDeclImg.cc
@@ -45,12 +45,12 @@ static void clear_colormap (img::DataMapping *dm)
 
 static void add_colormap (img::DataMapping *dm, double value, lay::color_t color)
 {
-  dm->false_color_nodes.push_back (std::make_pair (value, std::make_pair (QColor (color), QColor (color))));
+  dm->false_color_nodes.push_back (std::make_pair (value, std::make_pair (lay::Color (color), lay::Color (color))));
 }
 
 static void add_colormap2 (img::DataMapping *dm, double value, lay::color_t lcolor, lay::color_t rcolor)
 {
-  dm->false_color_nodes.push_back (std::make_pair (value, std::make_pair (QColor (lcolor), QColor (rcolor))));
+  dm->false_color_nodes.push_back (std::make_pair (value, std::make_pair (lay::Color (lcolor), lay::Color (rcolor))));
 }
 
 static size_t num_colormap_entries (const img::DataMapping *dm)
diff --git a/src/img/img/imgObject.cc b/src/img/img/imgObject.cc
index f8758b9d3..7f265252c 100644
--- a/src/img/img/imgObject.cc
+++ b/src/img/img/imgObject.cc
@@ -31,6 +31,7 @@
 #include "dbPolygonTools.h"
 #include "tlFileUtils.h"
 #include "tlUri.h"
+#include "tlThreads.h"
 
 #include <cmath>
 #include <cstring>
@@ -40,7 +41,6 @@
 #include <memory.h>
 
 #include <QImage>
-#include <QMutex>
 
 namespace img
 {
@@ -51,8 +51,8 @@ namespace img
 DataMapping::DataMapping ()
   : brightness (0.0), contrast (0.0), gamma (1.0), red_gain (1.0), green_gain (1.0), blue_gain (1.0)
 {
-  false_color_nodes.push_back (std::make_pair (0.0, std::make_pair (QColor (0, 0, 0), QColor (0, 0, 0))));
-  false_color_nodes.push_back (std::make_pair (1.0, std::make_pair (QColor (255, 255, 255), QColor (255, 255, 255))));
+  false_color_nodes.push_back (std::make_pair (0.0, std::make_pair (lay::Color (0, 0, 0), lay::Color (0, 0, 0))));
+  false_color_nodes.push_back (std::make_pair (1.0, std::make_pair (lay::Color (255, 255, 255), lay::Color (255, 255, 255))));
 }
 
 bool 
@@ -192,11 +192,11 @@ DataMapping::create_data_mapping (bool monochrome, double xmin, double xmax, uns
 
     for (unsigned int i = 1; i < false_color_nodes.size (); ++i) {
 
-      int h1, s1, v1;
-      false_color_nodes [i - 1].second.second.getHsv (&h1, &s1, &v1);
+      unsigned int h1, s1, v1;
+      false_color_nodes [i - 1].second.second.get_hsv (h1, s1, v1);
 
-      int h2, s2, v2;
-      false_color_nodes [i].second.first.getHsv (&h2, &s2, &v2);
+      unsigned int h2, s2, v2;
+      false_color_nodes [i].second.first.get_hsv (h2, s2, v2);
 
       //  The number of steps is chosen such that the full HSV band divides into approximately 200 steps
       double nsteps = 0.5 * sqrt (double (h1 - h2) * double (h1 - h2) + double (s1 - s2) * double (s1 - s2) + double (v1 - v2) * double (v1 - v2));
@@ -206,7 +206,7 @@ DataMapping::create_data_mapping (bool monochrome, double xmin, double xmax, uns
 
       for (int j = 0; j < n; ++j) {
 
-        QColor c = interpolated_color (false_color_nodes, x);
+        lay::Color c = interpolated_color (false_color_nodes, x);
 
         double y = 0.0;
         if (channel == 0) {
@@ -260,6 +260,57 @@ DataMapping::create_data_mapping (bool monochrome, double xmin, double xmax, uns
   return dm;
 }
 
+// --------------------------------------------------------------------------------------
+
+namespace
+{
+
+struct compare_first_of_node
+{
+  bool operator() (const std::pair <double, std::pair<lay::Color, lay::Color> > &a, const std::pair <double, std::pair<lay::Color, lay::Color> > &b) const
+  {
+    return a.first < b.first;
+  }
+};
+
+}
+
+lay::Color
+interpolated_color (const DataMapping::false_color_nodes_type &nodes, double x)
+{
+  if (nodes.size () < 1) {
+    return lay::Color ();
+  } else if (nodes.size () < 2) {
+    return x < nodes[0].first ? nodes[0].second.first : nodes[0].second.second;
+  } else {
+
+    std::vector<std::pair<double, std::pair<lay::Color, lay::Color> > >::const_iterator p = std::lower_bound (nodes.begin (), nodes.end (), std::make_pair (x, std::make_pair (lay::Color (), lay::Color ())), compare_first_of_node ());
+    if (p == nodes.end ()) {
+      return nodes.back ().second.second;
+    } else if (p == nodes.begin ()) {
+      return nodes.front ().second.first;
+    } else {
+
+      double x1 = p[-1].first;
+      double x2 = p->first;
+
+      unsigned int h1 = 0, s1 = 0, v1 = 0;
+      p[-1].second.second.get_hsv (h1, s1, v1);
+
+      unsigned int h2 = 0, s2 = 0, v2 = 0;
+      p->second.first.get_hsv (h2, s2, v2);
+
+      int h = int (0.5 + h1 + double(x - x1) * double (h2 - h1) / double(x2 - x1));
+      int s = int (0.5 + s1 + double(x - x1) * double (s2 - s1) / double(x2 - x1));
+      int v = int (0.5 + v1 + double(x - x1) * double (v2 - v1) / double(x2 - x1));
+
+      return lay::Color::from_hsv ((unsigned int) h, (unsigned int) s, (unsigned int) v);
+
+    }
+
+  }
+}
+
 // --------------------------------------------------------------------------------------
 //  img::DataHeader definition and implementation
 
@@ -690,7 +741,7 @@ private:
 
 static size_t make_id ()
 {
-  static QMutex id_lock;
+  static tl::Mutex id_lock;
   static size_t s_id_counter = 1;
 
   //  Get a new Id for the object. Id == 0 is reserved.
@@ -1283,7 +1334,7 @@ Object::from_string (const char *str, const char *base_dir)
 
         double x = 0.0;
         lay::ColorConverter cc;
-        QColor cl, cr;
+        lay::Color cl, cr;
         std::string s;
 
         m_data_mapping.false_color_nodes.clear ();
@@ -1654,7 +1705,7 @@ Object::to_string () const
     for (unsigned int i = 0; i < data_mapping ().false_color_nodes.size (); ++i) {
       os << data_mapping ().false_color_nodes[i].first;
       os << ",";
-      const std::pair<QColor, QColor> &clr = data_mapping ().false_color_nodes[i].second;
+      const std::pair<lay::Color, lay::Color> &clr = data_mapping ().false_color_nodes[i].second;
       os << tl::to_word_or_quoted_string (cc.to_string (clr.first));
       if (clr.first != clr.second) {
         os << ",";
diff --git a/src/img/img/imgObject.h b/src/img/img/imgObject.h
index c5dcdb467..1d3f734e1 100644
--- a/src/img/img/imgObject.h
+++ b/src/img/img/imgObject.h
@@ -33,13 +33,11 @@
 #include "dbMatrix.h"
 #include "dbPolygon.h"
 #include "tlDataMapping.h"
-#include "layViewOp.h"
+#include "layColor.h"
 
 #include <string>
 #include <vector>
 
-#include <QColor>
-
 namespace img {
   
 class DataHeader;
@@ -52,7 +50,7 @@ class DataHeader;
 struct IMG_PUBLIC DataMapping
 {
 public:
-  typedef std::vector< std::pair<double, std::pair<QColor, QColor> > > false_color_nodes_type;
+  typedef std::vector< std::pair<double, std::pair<lay::Color, lay::Color> > > false_color_nodes_type;
 
   /**
    *  @brief The constructor
@@ -139,6 +137,11 @@ public:
   tl::DataMappingBase *create_data_mapping (bool monochrome, double xmin, double xmax, unsigned int channel) const;
 };
 
+/**
+ *  @brief A helper function to interpolate a color in the color bar at a given x
+ */
+lay::Color interpolated_color (const DataMapping::false_color_nodes_type &nodes, double x);
+
 /**
  *  @brief A image object
  * 
diff --git a/src/img/img/imgPropertiesPage.cc b/src/img/img/imgPropertiesPage.cc
index fef5a1fa8..aec31b1b0 100644
--- a/src/img/img/imgPropertiesPage.cc
+++ b/src/img/img/imgPropertiesPage.cc
@@ -735,9 +735,9 @@ PropertiesPage::blue_spinbox_changed (double value)
 void  
 PropertiesPage::black_to_white ()
 {
-  std::vector <std::pair <double, std::pair<QColor, QColor> > > nodes;
-  nodes.push_back (std::make_pair (0.0, std::make_pair (QColor (0, 0, 0), QColor (0, 0, 0))));
-  nodes.push_back (std::make_pair (1.0, std::make_pair (QColor (255, 255, 255), QColor (255, 255, 255))));
+  std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > > nodes;
+  nodes.push_back (std::make_pair (0.0, std::make_pair (lay::Color (0, 0, 0), lay::Color (0, 0, 0))));
+  nodes.push_back (std::make_pair (1.0, std::make_pair (lay::Color (255, 255, 255), lay::Color (255, 255, 255))));
   false_color_control->set_nodes (nodes);
   emit edited ();
 }
@@ -745,9 +745,9 @@ PropertiesPage::black_to_white ()
 void  
 PropertiesPage::white_to_black ()
 {
-  std::vector <std::pair <double, std::pair<QColor, QColor> > > nodes;
-  nodes.push_back (std::make_pair (0.0, std::make_pair (QColor (255, 255, 255), QColor (255, 255, 255))));
-  nodes.push_back (std::make_pair (1.0, std::make_pair (QColor (0, 0, 0), QColor (0, 0, 0))));
+  std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > > nodes;
+  nodes.push_back (std::make_pair (0.0, std::make_pair (lay::Color (255, 255, 255), lay::Color (255, 255, 255))));
+  nodes.push_back (std::make_pair (1.0, std::make_pair (lay::Color (0, 0, 0), lay::Color (0, 0, 0))));
   false_color_control->set_nodes (nodes);
   emit edited ();
 }
@@ -755,9 +755,9 @@ PropertiesPage::white_to_black ()
 void  
 PropertiesPage::red_to_blue ()
 {
-  std::vector <std::pair <double, std::pair<QColor, QColor> > > nodes;
-  nodes.push_back (std::make_pair (0.0, std::make_pair (QColor (255, 0, 0), QColor (255, 0, 0))));
-  nodes.push_back (std::make_pair (1.0, std::make_pair (QColor (0, 0, 255), QColor (0, 0, 255))));
+  std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > > nodes;
+  nodes.push_back (std::make_pair (0.0, std::make_pair (lay::Color (255, 0, 0), lay::Color (255, 0, 0))));
+  nodes.push_back (std::make_pair (1.0, std::make_pair (lay::Color (0, 0, 255), lay::Color (0, 0, 255))));
   false_color_control->set_nodes (nodes);
   emit edited ();
 }
@@ -765,9 +765,9 @@ PropertiesPage::red_to_blue ()
 void  
 PropertiesPage::blue_to_red ()
 {
-  std::vector <std::pair <double, std::pair<QColor, QColor> > > nodes;
-  nodes.push_back (std::make_pair (0.0, std::make_pair (QColor (0, 0, 255), QColor (0, 0, 255))));
-  nodes.push_back (std::make_pair (1.0, std::make_pair (QColor (255, 0, 0), QColor (255, 0, 0))));
+  std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > > nodes;
+  nodes.push_back (std::make_pair (0.0, std::make_pair (lay::Color (0, 0, 255), lay::Color (0, 0, 255))));
+  nodes.push_back (std::make_pair (1.0, std::make_pair (lay::Color (255, 0, 0), lay::Color (255, 0, 0))));
   false_color_control->set_nodes (nodes);
   emit edited ();
 }
@@ -775,7 +775,7 @@ PropertiesPage::blue_to_red ()
 void  
 PropertiesPage::reverse_color_order ()
 {
-  std::vector <std::pair <double, std::pair<QColor, QColor> > > nodes (false_color_control->nodes ());
+  std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > > nodes (false_color_control->nodes ());
   for (size_t i = 0; i < nodes.size () / 2; ++i) {
     std::swap (nodes [i].second.second, nodes [nodes.size () - 1 - i].second.first);
     std::swap (nodes [i].second.first, nodes [nodes.size () - 1 - i].second.second);
diff --git a/src/img/img/imgStream.cc b/src/img/img/imgStream.cc
index 72dcb9c21..cb84b63b6 100644
--- a/src/img/img/imgStream.cc
+++ b/src/img/img/imgStream.cc
@@ -373,7 +373,7 @@ namespace {
 
   struct ColorMapConverter
   {
-    std::string to_string (const std::pair<double, std::pair<QColor, QColor> > &cm) const
+    std::string to_string (const std::pair<double, std::pair<lay::Color, lay::Color> > &cm) const
     {
       std::string s;
       s = tl::to_string (cm.first);
@@ -389,7 +389,7 @@ namespace {
       return s;
     }
 
-    void from_string (const std::string &s, std::pair<double, std::pair<QColor, QColor> > &cm) const
+    void from_string (const std::string &s, std::pair<double, std::pair<lay::Color, lay::Color> > &cm) const
     {
       tl::Extractor ex (s.c_str ());
 
@@ -427,7 +427,7 @@ tl::XMLStruct<ImageProxy> s_img_structure ("image-data",
   tl::make_member (&ImageProxy::max_value, &ImageProxy::set_max_value, "max-value") +
   tl::make_element (&ImageProxy::data_mapping, &ImageProxy::set_data_mapping, "data-mapping",
     tl::make_element (&img::DataMapping::false_color_nodes, "color-map",
-      tl::make_member<std::pair<double, std::pair<QColor, QColor> >, img::DataMapping::false_color_nodes_type::const_iterator, img::DataMapping::false_color_nodes_type, ColorMapConverter> (&img::DataMapping::false_color_nodes_type::begin, &img::DataMapping::false_color_nodes_type::end, &img::DataMapping::false_color_nodes_type::push_back, "color-map-entry", ColorMapConverter ())
+      tl::make_member<std::pair<double, std::pair<lay::Color, lay::Color> >, img::DataMapping::false_color_nodes_type::const_iterator, img::DataMapping::false_color_nodes_type, ColorMapConverter> (&img::DataMapping::false_color_nodes_type::begin, &img::DataMapping::false_color_nodes_type::end, &img::DataMapping::false_color_nodes_type::push_back, "color-map-entry", ColorMapConverter ())
     ) +
     tl::make_member (&img::DataMapping::brightness, "brightness") +
     tl::make_member (&img::DataMapping::contrast, "contrast") +
diff --git a/src/img/img/imgWidgets.cc b/src/img/img/imgWidgets.cc
index 587e77322..92952dac5 100644
--- a/src/img/img/imgWidgets.cc
+++ b/src/img/img/imgWidgets.cc
@@ -44,52 +44,6 @@ const int min_bar_height = 4;
 const double min_value_interval = 1e-3;
 const double epsilon = 1e-6;
 
-struct compare_first_of_node
-{
-  bool operator() (const std::pair <double, std::pair<QColor, QColor> > &a, const std::pair <double, std::pair<QColor, QColor> > &b) const
-  {
-    return a.first < b.first;
-  }
-};
-
-QColor
-interpolated_color (const std::vector<std::pair <double, std::pair<QColor, QColor> > > &nodes, double x)
-{
-  if (nodes.size () < 1) {
-    return QColor ();
-  } else if (nodes.size () < 2) {
-    return x < nodes[0].first ? nodes[0].second.first : nodes[0].second.second;
-  } else {
-
-    std::vector<std::pair<double, std::pair<QColor, QColor> > >::const_iterator p = std::lower_bound (nodes.begin (), nodes.end (), std::make_pair (x, std::make_pair (QColor (), QColor ())), compare_first_of_node ());
-    if (p == nodes.end ()) {
-      return nodes.back ().second.second;
-    } else if (p == nodes.begin ()) {
-      return nodes.front ().second.first;
-    } else {
-
-      double x1 = p[-1].first;
-      double x2 = p->first;
-
-      int h1 = 0, s1 = 0, v1 = 0;
-      p[-1].second.second.getHsv (&h1, &s1, &v1);
-
-      int h2 = 0, s2 = 0, v2 = 0;
-      p->second.first.getHsv (&h2, &s2, &v2);
-
-      int h = int (0.5 + h1 + double(x - x1) * double (h2 - h1) / double(x2 - x1));
-      int s = int (0.5 + s1 + double(x - x1) * double (s2 - s1) / double(x2 - x1));
-      int v = int (0.5 + v1 + double(x - x1) * double (v2 - v1) / double(x2 - x1));
-
-      QColor r;
-      r.setHsv (h, s, v);
-      return r;
-
-    }
-
-  }
-}
-
 // --------------------------------------------------------------------------------------------------------------------
 
 TwoColorWidget::TwoColorWidget (QWidget *parent)
@@ -173,8 +127,8 @@ TwoColorWidget::lock_changed (bool checked)
 ColorBar::ColorBar (QWidget *parent)
   : QWidget (parent), m_dragging (false), m_selected (-1)
 {
-  m_nodes.push_back (std::make_pair (0.0, std::make_pair (QColor (0, 0, 0), QColor (0, 0, 0))));
-  m_nodes.push_back (std::make_pair (1.0, std::make_pair (QColor (255, 255, 255), QColor (255, 255, 255))));
+  m_nodes.push_back (std::make_pair (0.0, std::make_pair (lay::Color (0, 0, 0), lay::Color (0, 0, 0))));
+  m_nodes.push_back (std::make_pair (1.0, std::make_pair (lay::Color (255, 255, 255), lay::Color (255, 255, 255))));
 }
 
 ColorBar::~ColorBar ()
@@ -206,7 +160,7 @@ void
 ColorBar::set_current_color (std::pair<QColor, QColor> c)
 {
   if (has_selection ()) {
-    m_nodes [m_selected].second = c;
+    m_nodes [m_selected].second = std::make_pair (lay::Color (c.first.rgb ()), lay::Color (c.second.rgb ()));
     emit color_mapping_changed ();
     update ();
   }
@@ -260,22 +214,35 @@ ColorBar::keyPressEvent (QKeyEvent *event)
   }
 }
 
+namespace
+{
+
+struct compare_first_of_node
+{
+  bool operator() (const std::pair <double, std::pair<lay::Color, lay::Color> > &a, const std::pair <double, std::pair<lay::Color, lay::Color> > &b) const
+  {
+    return a.first < b.first;
+  }
+};
+
+}
+
 void 
-ColorBar::set_nodes (const std::vector<std::pair<double, std::pair<QColor, QColor> > > &nodes)
+ColorBar::set_nodes (const std::vector<std::pair<double, std::pair<lay::Color, lay::Color> > > &nodes)
 {
   m_nodes = nodes;
 
   std::sort (m_nodes.begin (), m_nodes.end (), compare_first_of_node ());
 
   if (m_nodes.size () == 0 || fabs (m_nodes[0].first) > epsilon) {
-    m_nodes.insert (m_nodes.begin (), std::make_pair (0.0, std::make_pair (QColor (0, 0, 0), QColor (0, 0, 0))));
+    m_nodes.insert (m_nodes.begin (), std::make_pair (0.0, std::make_pair (lay::Color (0, 0, 0), lay::Color (0, 0, 0))));
   } else {
     m_nodes[0].first = 0.0;
   }
 
-  std::vector <std::pair <double, std::pair<QColor, QColor> > >::iterator w = m_nodes.begin ();
-  std::vector <std::pair <double, std::pair<QColor, QColor> > >::const_iterator nn = m_nodes.begin ();
-  for (std::vector <std::pair <double, std::pair<QColor, QColor> > >::const_iterator n = m_nodes.begin () + 1; n != m_nodes.end (); ++n) {
+  std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > >::iterator w = m_nodes.begin ();
+  std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > >::const_iterator nn = m_nodes.begin ();
+  for (std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > >::const_iterator n = m_nodes.begin () + 1; n != m_nodes.end (); ++n) {
     if (fabs (nn->first - n->first) > min_value_interval) {
       *w++ = *nn;
       nn = n;
@@ -288,7 +255,7 @@ ColorBar::set_nodes (const std::vector<std::pair<double, std::pair<QColor, QColo
   if (m_nodes.back ().first > 1.0 - min_value_interval) {
     m_nodes.back ().first = 1.0;
   } else {
-    m_nodes.push_back (std::make_pair (1.0, std::make_pair (QColor (255, 255, 255), QColor (255, 255, 255))));
+    m_nodes.push_back (std::make_pair (1.0, std::make_pair (lay::Color (255, 255, 255), lay::Color (255, 255, 255))));
   }
 
   m_selected = -1;
@@ -313,8 +280,8 @@ ColorBar::mousePressEvent (QMouseEvent *event)
     double xx = double (event->x () - xl) / double (xr - xl);
 
     double dmin = 100.0;
-    std::vector<std::pair<double, std::pair<QColor, QColor> > >::const_iterator pmin = m_nodes.end ();
-    for (std::vector<std::pair<double, std::pair<QColor, QColor> > >::const_iterator p = m_nodes.begin (); p != m_nodes.end (); ++p) {
+    std::vector<std::pair<double, std::pair<lay::Color, lay::Color> > >::const_iterator pmin = m_nodes.end ();
+    for (std::vector<std::pair<double, std::pair<lay::Color, lay::Color> > >::const_iterator p = m_nodes.begin (); p != m_nodes.end (); ++p) {
       double d = fabs (p->first - xx);
       if (d < 0.05 && d < dmin) {
         dmin = d;
@@ -323,9 +290,10 @@ ColorBar::mousePressEvent (QMouseEvent *event)
     }
 
     if (pmin != m_nodes.end ()) {
-      m_selected = int (std::distance (std::vector<std::pair<double, std::pair<QColor, QColor> > >::const_iterator (m_nodes.begin ()), pmin));
+      m_selected = int (std::distance (std::vector<std::pair<double, std::pair<lay::Color, lay::Color> > >::const_iterator (m_nodes.begin ()), pmin));
       emit selection_changed ();
-      emit selection_changed (m_nodes [m_selected].second);
+      std::pair<lay::Color, lay::Color> cp = m_nodes [m_selected].second;
+      emit selection_changed (std::make_pair (QColor (cp.first.rgb ()), QColor (cp.second.rgb ())));
       m_dragging = true;
       update ();
     } else {
@@ -359,13 +327,14 @@ ColorBar::mouseDoubleClickEvent (QMouseEvent *event)
 
     double xx = double (event->x () - xl) / double (xr - xl);
 
-    std::vector<std::pair<double, std::pair<QColor, QColor> > >::iterator p = std::lower_bound (m_nodes.begin (), m_nodes.end (), std::make_pair (xx, std::make_pair (QColor (), QColor ())), compare_first_of_node ());
+    std::vector<std::pair<double, std::pair<lay::Color, lay::Color> > >::iterator p = std::lower_bound (m_nodes.begin (), m_nodes.end (), std::make_pair (xx, std::make_pair (lay::Color (), lay::Color ())), compare_first_of_node ());
     if (p != m_nodes.begin () && p != m_nodes.end ()) {
       m_selected = int (std::distance (m_nodes.begin (), p));
-      QColor ci = interpolated_color (m_nodes, xx);
+      lay::Color ci = interpolated_color (m_nodes, xx);
       m_nodes.insert (p, std::make_pair (xx, std::make_pair (ci, ci)));
       emit selection_changed ();
-      emit selection_changed (m_nodes [m_selected].second);
+      std::pair<lay::Color, lay::Color> cp = m_nodes [m_selected].second;
+      emit selection_changed (std::make_pair (QColor (cp.first.rgb ()), QColor (cp.second.rgb ())));
       emit color_mapping_changed ();
       update ();
     }
@@ -440,9 +409,9 @@ ColorBar::paintEvent (QPaintEvent *)
     if (xr != xl) {
       xx = double (x - xl) / double (xr - xl);
     }
-    QColor c = interpolated_color (m_nodes, xx);
+    lay::Color c = interpolated_color (m_nodes, xx);
 
-    painter.fillRect (x, yb - hbar, 1, hbar + 1, QBrush (c));
+    painter.fillRect (x, yb - hbar, 1, hbar + 1, QBrush (QColor (c.rgb ())));
 
   }
 
diff --git a/src/img/img/imgWidgets.h b/src/img/img/imgWidgets.h
index d0ce8ed63..06cef78ef 100644
--- a/src/img/img/imgWidgets.h
+++ b/src/img/img/imgWidgets.h
@@ -24,6 +24,8 @@
 #define HDR_imgWidgets
 
 #include "layWidgets.h"
+#include "layColor.h"
+#include "imgObject.h"
 
 #include <QObject>
 #include <QWidget>
@@ -38,13 +40,6 @@ class QPaintEvent;
 namespace img
 {
 
-/**
- *  @brief A helper function to interpolate a color in the color bar at a given x
- *
- *  TODO: move this somewhere else.
- */
-QColor interpolated_color (const std::vector<std::pair <double, std::pair<QColor, QColor> > > &nodes, double x);
-
 /**
  *  @brief A two-color widget
  *
@@ -114,9 +109,9 @@ public:
     return m_selected >= 0;
   }
 
-  void set_nodes (const std::vector <std::pair <double, std::pair<QColor, QColor> > > &nodes);
+  void set_nodes (const std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > > &nodes);
 
-  const std::vector <std::pair <double, std::pair<QColor, QColor> > > &nodes () const
+  const std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > > &nodes () const
   {
     return m_nodes;
   }
@@ -135,7 +130,7 @@ signals:
 private:
   bool m_dragging;
   int m_selected;
-  std::vector <std::pair <double, std::pair<QColor, QColor> > > m_nodes;
+  std::vector <std::pair <double, std::pair<lay::Color, lay::Color> > > m_nodes;
   std::vector <size_t> m_histogram;
 };
 
diff --git a/src/img/unit_tests/imgFile.cc b/src/img/unit_tests/imgFile.cc
index 49719aa02..5daf917f2 100644
--- a/src/img/unit_tests/imgFile.cc
+++ b/src/img/unit_tests/imgFile.cc
@@ -45,9 +45,9 @@ TEST(1_FloatMono)
   dm.gamma = 1.5;
   dm.brightness = 1.25;
   dm.false_color_nodes.clear ();
-  dm.false_color_nodes.push_back (std::make_pair (0.0, std::make_pair (QColor (0, 0, 0), QColor (0, 0, 0))));
-  dm.false_color_nodes.push_back (std::make_pair (0.5, std::make_pair (QColor (255, 0, 0), QColor (0, 255, 0))));
-  dm.false_color_nodes.push_back (std::make_pair (1.0, std::make_pair (QColor (255, 255, 255), QColor (255, 255, 255))));
+  dm.false_color_nodes.push_back (std::make_pair (0.0, std::make_pair (lay::Color (0, 0, 0), lay::Color (0, 0, 0))));
+  dm.false_color_nodes.push_back (std::make_pair (0.5, std::make_pair (lay::Color (255, 0, 0), lay::Color (0, 255, 0))));
+  dm.false_color_nodes.push_back (std::make_pair (1.0, std::make_pair (lay::Color (255, 255, 255), lay::Color (255, 255, 255))));
   image.set_data_mapping (dm);
 
   image.set_pixel (0, 0, 0.25);
diff --git a/src/img/unit_tests/imgObject.cc b/src/img/unit_tests/imgObject.cc
index 7eaa24198..1dfabda0c 100644
--- a/src/img/unit_tests/imgObject.cc
+++ b/src/img/unit_tests/imgObject.cc
@@ -101,8 +101,8 @@ TEST(1)
   dm.red_gain = 1.25;
   dm.green_gain = 0.75;
   dm.blue_gain = 2.5;
-  QColor c (128, 255, 64);
-  QColor c2 (64, 32, 192);
+  lay::Color c (128, 255, 64);
+  lay::Color c2 (64, 32, 192);
   dm.false_color_nodes.insert (dm.false_color_nodes.begin () + 1, std::make_pair (0.5, std::make_pair (c, c)));
   image.set_data_mapping (dm);
   EXPECT_EQ (copy1.equals (&image), false);
@@ -226,7 +226,7 @@ TEST(2)
     dm.red_gain = 1.25;
     dm.green_gain = 0.75;
     dm.blue_gain = 2.5;
-    QColor c (128, 255, 64);
+    lay::Color c (128, 255, 64);
     dm.false_color_nodes.insert (dm.false_color_nodes.begin () + 1, std::make_pair (0.5, std::make_pair (c, c)));
     image.set_data_mapping (dm);
     EXPECT_EQ (copy1.equals (&image), false);
diff --git a/src/laybasic/laybasic/layColor.cc b/src/laybasic/laybasic/layColor.cc
index 67e0c700e..ac486cdbb 100644
--- a/src/laybasic/laybasic/layColor.cc
+++ b/src/laybasic/laybasic/layColor.cc
@@ -23,6 +23,7 @@
 
 #include "layColor.h"
 #include "tlString.h"
+#include "tlMath.h"
 
 #include <ctype.h>
 
@@ -116,4 +117,82 @@ Color::is_valid () const
   return (m_color & 0xff000000) != 0;
 }
 
+void
+Color::get_hsv (unsigned int &hue, unsigned int &saturation, unsigned int &value) const
+{
+  double r = double (red ()) / 255.0;
+  double g = double (green ()) / 255.0;
+  double b = double (blue ()) / 255.0;
+
+  double max = std::max (r, std::max (g, b));
+  double min = std::min (r, std::min (g, b));
+  double delta = max - min;
+
+  value = (unsigned int) tl::round (255.0 * max, 1);
+  hue = 0;
+  saturation = 0;
+
+  if (! tl::equal (delta, 0.0)) {
+
+    saturation = (unsigned int) tl::round (255.0 * delta / max, 1);
+    double h = 0.0;
+    if (tl::equal (r, max)) {
+      h = (g - b) / delta;
+    } else if (tl::equal (g, max)) {
+      h = 2.0f + (b - r) / delta;
+    } else if (tl::equal (b, max)) {
+      h = 4.0f + (r - g) / delta;
+    }
+    h *= 60.0;
+    if (tl::less (h, 0.0)) {
+      h += 360.0;
+    }
+
+    hue = (unsigned int) tl::round (h, 1);
+
+  }
+}
+
+static lay::Color color_d (double r, double g, double b)
+{
+  return lay::Color (tl::round (r * 255.0, 1), tl::round (g * 255.0, 1), tl::round (b * 255.0, 1));
+}
+
+lay::Color
+Color::from_hsv (unsigned int hue, unsigned int saturation, unsigned int value)
+{
+  if (saturation == 0) {
+    return lay::Color (value, value, value);
+  }
+
+  hue = (hue + 360) % 360;
+
+  double h = double (hue) / 60.0;
+  double s = double (saturation) / 255.0;
+  double v = double (value) / 255.0;
+
+  int i = int (tl::round_down (h, 1));
+  double f = (i & 1) != 0 ? h - i : 1.0 - h + i;
+  double p = v * (1.0 - s);
+  double q = v * (1.0 - s * f);
+
+  switch (i) {
+  case 0:
+    return color_d (v, q, p);
+  case 1:
+    return color_d (q, v, p);
+  case 2:
+    return color_d (p, v, q);
+  case 3:
+    return color_d (p, q, v);
+  case 4:
+    return color_d (q, p, v);
+  case 5:
+    return color_d (v, p, q);
+  default:
+    return lay::Color ();
+  }
+
+}
+
 }
diff --git a/src/laybasic/laybasic/layColor.h b/src/laybasic/laybasic/layColor.h
index 77cccebc8..79725ecfb 100644
--- a/src/laybasic/laybasic/layColor.h
+++ b/src/laybasic/laybasic/layColor.h
@@ -142,6 +142,19 @@ public:
     return (m_color & 0xff);
   }
 
+  /**
+   *  @brief Gets the HSV color components
+   *  hue: 0..359
+   *  saturation: 0..255
+   *  value: 0..255
+   */
+  void get_hsv (unsigned int &hue, unsigned int &saturation, unsigned int &value) const;
+
+  /**
+   *  @brief Creates the color from a HSV color
+   */
+  static lay::Color from_hsv (unsigned int hue, unsigned int saturation, unsigned int value);
+
 private:
   color_t m_color;
 };
diff --git a/src/laybasic/unit_tests/layColorTests.cc b/src/laybasic/unit_tests/layColorTests.cc
index c1d44c744..8da8e208b 100644
--- a/src/laybasic/unit_tests/layColorTests.cc
+++ b/src/laybasic/unit_tests/layColorTests.cc
@@ -116,3 +116,104 @@ TEST(7)
   EXPECT_EQ (QColor (16, 32, 48, 128).rgb (), 0xff102030);
 #endif
 }
+
+TEST(8)
+{
+  unsigned int h, s, v;
+  int ih, is, iv;
+  lay::Color c = lay::Color (16, 32, 48);
+  c.get_hsv (h, s, v);
+  EXPECT_EQ (h, 210);
+  EXPECT_EQ (s, 170);
+  EXPECT_EQ (v, 48);
+
+  EXPECT_EQ (lay::Color::from_hsv (h, s, v).to_string (), "#102030");
+
+#if defined(HAVE_QT)
+  QColor qc = QColor (16, 32, 48);
+  qc.getHsv (&ih, &is, &iv);
+  EXPECT_EQ (ih, 210);
+  EXPECT_EQ (is, 170);
+  EXPECT_EQ (iv, 48);
+#endif
+
+  c = lay::Color (32, 16, 48);
+  c.get_hsv (h, s, v);
+  EXPECT_EQ (h, 270);
+  EXPECT_EQ (s, 170);
+  EXPECT_EQ (v, 48);
+
+  EXPECT_EQ (lay::Color::from_hsv (h, s, v).to_string (), "#201030");
+
+#if defined(HAVE_QT)
+  qc = QColor (32, 16, 48);
+  qc.getHsv (&ih, &is, &iv);
+  EXPECT_EQ (ih, 270);
+  EXPECT_EQ (is, 170);
+  EXPECT_EQ (iv, 48);
+#endif
+
+  c = lay::Color (32, 48, 16);
+  c.get_hsv (h, s, v);
+  EXPECT_EQ (h, 90);
+  EXPECT_EQ (s, 170);
+  EXPECT_EQ (v, 48);
+
+  EXPECT_EQ (lay::Color::from_hsv (h, s, v).to_string (), "#203010");
+
+#if defined(HAVE_QT)
+  qc = QColor (32, 48, 16);
+  qc.getHsv (&ih, &is, &iv);
+  EXPECT_EQ (ih, 90);
+  EXPECT_EQ (is, 170);
+  EXPECT_EQ (iv, 48);
+#endif
+
+  c = lay::Color (48, 32, 16);
+  c.get_hsv (h, s, v);
+  EXPECT_EQ (h, 30);
+  EXPECT_EQ (s, 170);
+  EXPECT_EQ (v, 48);
+
+  EXPECT_EQ (lay::Color::from_hsv (h, s, v).to_string (), "#302010");
+
+#if defined(HAVE_QT)
+  qc = QColor (48, 32, 16);
+  qc.getHsv (&ih, &is, &iv);
+  EXPECT_EQ (ih, 30);
+  EXPECT_EQ (is, 170);
+  EXPECT_EQ (iv, 48);
+#endif
+
+  c = lay::Color (48, 16, 32);
+  c.get_hsv (h, s, v);
+  EXPECT_EQ (h, 330);
+  EXPECT_EQ (s, 170);
+  EXPECT_EQ (v, 48);
+
+  EXPECT_EQ (lay::Color::from_hsv (h, s, v).to_string (), "#301020");
+
+#if defined(HAVE_QT)
+  qc = QColor (48, 16, 32);
+  qc.getHsv (&ih, &is, &iv);
+  EXPECT_EQ (ih, 330);
+  EXPECT_EQ (is, 170);
+  EXPECT_EQ (iv, 48);
+#endif
+
+  c = lay::Color (16, 48, 32);
+  c.get_hsv (h, s, v);
+  EXPECT_EQ (h, 150);
+  EXPECT_EQ (s, 170);
+  EXPECT_EQ (v, 48);
+
+  EXPECT_EQ (lay::Color::from_hsv (h, s, v).to_string (), "#103020");
+
+#if defined(HAVE_QT)
+  qc = QColor (16, 48, 32);
+  qc.getHsv (&ih, &is, &iv);
+  EXPECT_EQ (ih, 150);
+  EXPECT_EQ (is, 170);
+  EXPECT_EQ (iv, 48);
+#endif
+}