diff --git a/src/laybasic/laybasic/layNetlistBrowserModel.cc b/src/laybasic/laybasic/layNetlistBrowserModel.cc
index 025d75823..2395919a6 100644
--- a/src/laybasic/laybasic/layNetlistBrowserModel.cc
+++ b/src/laybasic/laybasic/layNetlistBrowserModel.cc
@@ -164,7 +164,7 @@ QColor
 NetColorizer::color_of_net (const db::Net *net) const
 {
   if (! net) {
-    return m_marker_color;
+    return QColor ();
   }
 
   std::map<const db::Net *, QColor>::const_iterator c = m_custom_color.find (net);
@@ -177,7 +177,7 @@ NetColorizer::color_of_net (const db::Net *net) const
     size_t index = index_from_attr (net, circuit->begin_nets (), circuit->end_nets (), m_net_index_by_object);
     return m_auto_colors.color_by_index ((unsigned int) index);
   } else {
-    return m_marker_color;
+    return QColor ();
   }
 }
 
@@ -1650,9 +1650,9 @@ NetlistBrowserModel::circuit_from_id (void *id) const
   if (c == m_circuit_by_index.end ()) {
 
     c = m_circuit_by_index.insert (std::make_pair (index, (db::Circuit *) 0)).first;
-    for (db::Netlist::circuit_iterator i = netlist ()->begin_circuits (); i != netlist ()->end_circuits (); ++i) {
+    for (db::Netlist::top_down_circuit_iterator i = netlist ()->begin_top_down (); i != netlist ()->end_top_down (); ++i) {
       if (index-- == 0) {
-        c->second = i.operator-> ();
+        c->second = *i;
         break;
       }
     }
diff --git a/src/laybasic/laybasic/layNetlistBrowserModel.h b/src/laybasic/laybasic/layNetlistBrowserModel.h
index a5c355400..28e3f0211 100644
--- a/src/laybasic/laybasic/layNetlistBrowserModel.h
+++ b/src/laybasic/laybasic/layNetlistBrowserModel.h
@@ -56,6 +56,11 @@ public:
 
   QColor color_of_net (const db::Net *net) const;
 
+  const QColor &marker_color () const
+  {
+    return m_marker_color;
+  }
+
   void begin_changes ();
   void end_changes ();
 
diff --git a/src/laybasic/laybasic/layNetlistBrowserPage.cc b/src/laybasic/laybasic/layNetlistBrowserPage.cc
index e3178b23c..32603aa21 100644
--- a/src/laybasic/laybasic/layNetlistBrowserPage.cc
+++ b/src/laybasic/laybasic/layNetlistBrowserPage.cc
@@ -88,7 +88,8 @@ NetlistBrowserPage::NetlistBrowserPage (QWidget * /*parent*/)
     m_signals_enabled (true),
     m_enable_updates (true),
     m_update_needed (true),
-    mp_info_dialog (0)
+    mp_info_dialog (0),
+    dm_update_highlights (this, &NetlistBrowserPage::update_highlights)
 {
   Ui::NetlistBrowserPage::setupUi (this);
 
@@ -241,7 +242,7 @@ NetlistBrowserPage::eventFilter (QObject *watched, QEvent *event)
 void
 NetlistBrowserPage::layer_list_changed (int)
 {
-  update_highlights ();
+  dm_update_highlights ();
 }
 
 void
@@ -775,7 +776,7 @@ NetlistBrowserPage::produce_highlights_for_device (const db::Device *device, siz
   const db::Layout *layout = mp_database->internal_layout ();
   db::ICplxTrans device_trans = trans_for (device, layout->dbu (), db::DCplxTrans (device->position () - db::DPoint ()));
 
-  QColor color = make_valid_color (m_colorizer.color_of_net (0));
+  QColor color = make_valid_color (m_colorizer.marker_color ());
   db::Box device_bbox = bbox_for_device (layout, device);
   if (device_bbox.empty ()) {
     return false;
@@ -801,7 +802,7 @@ NetlistBrowserPage::produce_highlights_for_subcircuit (const db::SubCircuit *sub
   const db::Layout *layout = mp_database->internal_layout ();
   db::ICplxTrans subcircuit_trans = trans_for (subcircuit, layout->dbu (), subcircuit->trans ());
 
-  QColor color = make_valid_color (m_colorizer.color_of_net (0));
+  QColor color = make_valid_color (m_colorizer.marker_color ());
   db::Box circuit_bbox = bbox_for_subcircuit (layout, subcircuit);
   if (circuit_bbox.empty ()) {
     return false;
@@ -830,7 +831,8 @@ NetlistBrowserPage::produce_highlights_for_net (const db::Net *net, size_t &n_ma
   db::cell_index_type cell_index = net->circuit ()->cell_index ();
   size_t cluster_id = net->cluster_id ();
 
-  QColor net_color = make_valid_color (m_colorizer.color_of_net (net));
+  QColor net_color = m_colorizer.color_of_net (net);
+  QColor fallback_color = make_valid_color (m_colorizer.marker_color ());
 
   const db::Connectivity &conn = mp_database->connectivity ();
   for (db::Connectivity::layer_iterator layer = conn.begin_layers (); layer != conn.end_layers (); ++layer) {
@@ -848,11 +850,16 @@ NetlistBrowserPage::produce_highlights_for_net (const db::Net *net, size_t &n_ma
       mp_markers.push_back (new lay::Marker (mp_view, m_cv_index));
       mp_markers.back ()->set (*shapes, net_trans * shapes.trans (), tv);
 
-      if (! m_use_original_colors || display == display_by_lp.end ()) {
+      if (net_color.isValid ()) {
 
         mp_markers.back ()->set_color (net_color);
         mp_markers.back ()->set_frame_color (net_color);
 
+      } else if (! m_use_original_colors || display == display_by_lp.end ()) {
+
+        mp_markers.back ()->set_color (fallback_color);
+        mp_markers.back ()->set_frame_color (fallback_color);
+
       } else if (display != display_by_lp.end ()) {
 
         mp_markers.back ()->set_line_width (display->second->width (true));
diff --git a/src/laybasic/laybasic/layNetlistBrowserPage.h b/src/laybasic/laybasic/layNetlistBrowserPage.h
index b50e21255..708e05484 100644
--- a/src/laybasic/laybasic/layNetlistBrowserPage.h
+++ b/src/laybasic/laybasic/layNetlistBrowserPage.h
@@ -184,6 +184,7 @@ private:
   std::vector<const db::Device *> m_current_devices;
   std::vector<const db::SubCircuit *> m_current_subcircuits;
   lay::NetInfoDialog *mp_info_dialog;
+  tl::DeferredMethod<NetlistBrowserPage> dm_update_highlights;
 
   void add_to_history (void *id, bool fwd);
   void navigate_to (void *id, bool forward = true);