diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 955c76e9f..c3e780041 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -1692,15 +1692,27 @@ void GCode::process_layer(
     }
 
     // we should add or not colorprint_change in respect to nozzle_diameter count instead of really used extruders count
-    if (colorprint_change && print./*extruders()*/config().nozzle_diameter.size()==1)
-    {
-        // add tag for analyzer
-        gcode += "; " + GCodeAnalyzer::Color_Change_Tag + "\n";
-        // add tag for time estimator
-        gcode += "; " + GCodeTimeEstimator::Color_Change_Tag + "\n";
-        //  #ys_FIXME_COLOR
-        // gcode += "M600\n";
-        gcode += custom_code + "\n";
+    //  #ys_FIXME_COLOR
+    // if (colorprint_change && print./*extruders()*/config().nozzle_diameter.size()==1)
+    // {
+    //     // add tag for analyzer
+    //     gcode += "; " + GCodeAnalyzer::Color_Change_Tag + "\n";
+    //     // add tag for time estimator
+    //     gcode += "; " + GCodeTimeEstimator::Color_Change_Tag + "\n";
+    //     
+    //     gcode += "M600\n";
+    // }
+    if (colorprint_change) {
+        if (print.config().nozzle_diameter.size() == 1)
+        {
+            // add tag for analyzer
+            gcode += "; " + GCodeAnalyzer::Color_Change_Tag + "\n";
+            // add tag for time estimator
+            gcode += "; " + GCodeTimeEstimator::Color_Change_Tag + "\n";
+            if (custom_code == "tool_change")
+                custom_code = "M600"; 
+            gcode += custom_code + "\n";
+        }
     }
 
 
diff --git a/src/libslic3r/Model.cpp b/src/libslic3r/Model.cpp
index 6123be037..0bb2edfc4 100644
--- a/src/libslic3r/Model.cpp
+++ b/src/libslic3r/Model.cpp
@@ -586,14 +586,15 @@ std::string Model::propose_export_file_name_and_path(const std::string &new_exte
     return boost::filesystem::path(this->propose_export_file_name_and_path()).replace_extension(new_extension).string();
 }
 
-std::vector<std::pair<double, DynamicPrintConfig>> Model:: get_custom_tool_changes(double default_layer_height) const
+std::vector<std::pair<double, DynamicPrintConfig>> Model::get_custom_tool_changes(double default_layer_height, size_t num_extruders) const
 {
     std::vector<std::pair<double, DynamicPrintConfig>> custom_tool_changes;
     if (!custom_gcode_per_height.empty()) {
         for (const CustomGCode& custom_gcode : custom_gcode_per_height)
             if (custom_gcode.gcode == "tool_change") {
                 DynamicPrintConfig config;
-                config.set_key_value("extruder", new ConfigOptionInt(custom_gcode.extruder));
+                // If extruder count in PrinterSettings was changed, use default (0) extruder for extruders, more than num_extruders
+                config.set_key_value("extruder", new ConfigOptionInt(custom_gcode.extruder > num_extruders ? 0 : custom_gcode.extruder));
                 // For correct extruders(tools) changing, we should decrease custom_gcode.height value by one default layer height
                 custom_tool_changes.push_back({ custom_gcode.height - default_layer_height, config });
             }
diff --git a/src/libslic3r/Model.hpp b/src/libslic3r/Model.hpp
index d78dbdfa6..aac6cde06 100644
--- a/src/libslic3r/Model.hpp
+++ b/src/libslic3r/Model.hpp
@@ -837,7 +837,7 @@ public:
     std::string   propose_export_file_name_and_path(const std::string &new_extension) const;
 
     // from custom_gcode_per_height get just tool_change codes
-    std::vector<std::pair<double, DynamicPrintConfig>> get_custom_tool_changes(double default_layer_height) const;
+    std::vector<std::pair<double, DynamicPrintConfig>> get_custom_tool_changes(double default_layer_height, size_t num_extruders) const;
 
 private:
 	explicit Model(int) : ObjectBase(-1) { assert(this->id().invalid()); };
diff --git a/src/libslic3r/Print.cpp b/src/libslic3r/Print.cpp
index d3451265e..a8d905efe 100644
--- a/src/libslic3r/Print.cpp
+++ b/src/libslic3r/Print.cpp
@@ -834,7 +834,8 @@ Print::ApplyStatus Print::apply(const Model &model, DynamicPrintConfig new_full_
     for (PrintObject *print_object : m_objects)
         print_object_status.emplace(PrintObjectStatus(print_object));
 
-    std::vector<std::pair<double, DynamicPrintConfig>> custom_tool_changes = m_model.get_custom_tool_changes(m_default_object_config.layer_height);
+    std::vector<std::pair<double, DynamicPrintConfig>> custom_tool_changes = 
+        m_model.get_custom_tool_changes(m_default_object_config.layer_height, num_extruders);
 
     // 3) Synchronize ModelObjects & PrintObjects.
     for (size_t idx_model_object = 0; idx_model_object < model.objects.size(); ++ idx_model_object) {
diff --git a/src/slic3r/GUI/GUI_Preview.cpp b/src/slic3r/GUI/GUI_Preview.cpp
index 5d0deaaad..91ffa4a5a 100644
--- a/src/slic3r/GUI/GUI_Preview.cpp
+++ b/src/slic3r/GUI/GUI_Preview.cpp
@@ -500,9 +500,19 @@ void Preview::reset_sliders()
 void Preview::update_sliders(const std::vector<double>& layers_z, bool keep_z_range)
 {
     m_enabled = true;
+    // update extruder selector
+    if (wxGetApp().extruders_edited_cnt() != m_extruder_selector->GetCount()-1)
+    {
+        int selection = m_extruder_selector->GetSelection();
+        update_extruder_selector();
+        if (selection >= m_extruder_selector->GetCount())
+            selection = 0;
+        m_extruder_selector->SetSelection(selection);
+    }
+
     update_double_slider(layers_z, keep_z_range);
     m_double_slider_sizer->Show((size_t)0);
-    if (m_slider->GetManipulationState() != DoubleSlider::msMultiExtruder)
+    if (m_slider->GetManipulationState() == DoubleSlider::msSingleExtruder)
         m_double_slider_sizer->GetItem(size_t(0))->GetSizer()->Hide((size_t)0);
     Layout();
 }
@@ -560,7 +570,7 @@ void Preview::on_checkbox_legend(wxCommandEvent& evt)
     m_canvas_widget->Refresh();
 }
 
-void Preview::update_view_type()
+void Preview::update_view_type(bool slice_completed)
 {
     const DynamicPrintConfig& config = wxGetApp().preset_bundle->project_config;
 
@@ -574,8 +584,8 @@ void Preview::update_view_type()
                                     _(L("Feature type"));
     */
 
-    const wxString& choice = !wxGetApp().plater()->model().custom_gcode_per_height.empty()// &&
-                             /*wxGetApp().extruders_edited_cnt()==1*/ ? 
+    const wxString& choice = !wxGetApp().plater()->model().custom_gcode_per_height.empty() &&
+                             (wxGetApp().extruders_edited_cnt()==1 || !slice_completed) ? 
                                 _(L("Color Print")) :
                                 config.option<ConfigOptionFloats>("wiping_volumes_matrix")->values.size() > 1 ?
                                     _(L("Tool")) : 
@@ -590,25 +600,39 @@ void Preview::update_view_type()
     }
 }
 
+void Preview::update_extruder_selector()
+{
+    m_extruder_selector->Clear();
+
+    m_extruder_selector->Append("Whole print");
+    const int extruder_cnt = wxGetApp().extruders_edited_cnt();
+    int i = 0;
+    while (i < extruder_cnt)
+    {
+        i++;
+        m_extruder_selector->Append(wxString::Format("Extruder %d", i));
+    }
+}
+
 void Preview::create_double_slider()
 {
     m_slider = new DoubleSlider(this, wxID_ANY, 0, 0, 0, 100);
     // #ys_FIXME_COLOR
     // m_double_slider_sizer->Add(m_slider, 0, wxEXPAND, 0);
 
-    auto extruder_selector = new wxComboBox(this, wxID_ANY);
-    extruder_selector->Append("Whole print");
-    int extruder_cnt = wxGetApp().extruders_edited_cnt();
-    int i = 0;
-    while (i < extruder_cnt)
+    m_extruder_selector = new wxComboBox(this, wxID_ANY);
+    update_extruder_selector();
+    m_extruder_selector->SetSelection(0);
+    m_extruder_selector->Bind(wxEVT_COMBOBOX, [this](wxCommandEvent& evt)
     {
-        i++;
-        extruder_selector->Append(wxString::Format("Extruder %d", i));
-    }
-    extruder_selector->SetSelection(0);
+        m_slider->SetManipulationState(m_extruder_selector->GetSelection() == 0 ? 
+                                       DoubleSlider::msMultiExtruderWholePrint :
+                                       DoubleSlider::msMultiExtruder);
+    });
+    m_extruder_selector->Disable(); // temporary disabled to suppress extruder selection
 
     auto sizer = new wxBoxSizer(wxVERTICAL);
-    sizer->Add(extruder_selector, 0, wxEXPAND, 0);
+    sizer->Add(m_extruder_selector, 0, wxEXPAND, 0);
     sizer->Add(m_slider, 1, wxEXPAND, 0);
 
     m_double_slider_sizer->Add(sizer, 0, wxEXPAND, 0);
@@ -627,7 +651,7 @@ void Preview::create_double_slider()
         model.custom_gcode_per_height = m_slider->GetTicksValues_();
         m_schedule_background_process();
 
-        update_view_type();
+        update_view_type(false);
 
         reload_print();
     });
@@ -733,16 +757,14 @@ void Preview::update_double_slider(const std::vector<double>& layers_z, bool kee
     // m_slider->EnableTickManipulation(color_print_enable);
 
     m_slider->EnableTickManipulation(color_print_enable);
-    m_slider->SetManipulationState(DoubleSlider::msSingleExtruder);
-    if (color_print_enable) {
-        const DynamicPrintConfig& cfg = wxGetApp().preset_bundle->printers.get_edited_preset().config;
-        if (cfg.opt<ConfigOptionFloats>("nozzle_diameter")->values.size() > 1) {
-            // ys_TODO : fill is_detected_one_extruder_print value
-            bool is_detected_one_extruder_print = wxGetApp().plater()->fff_print().extruders().size() == 1;
-            m_slider->SetManipulationState(is_detected_one_extruder_print ? 
-                                           DoubleSlider::msMultiExtruderSimple : DoubleSlider::msMultiExtruder);
-        }
+    if (color_print_enable && wxGetApp().extruders_edited_cnt() > 1) {
+        //bool is_detected_full_print = //wxGetApp().plater()->fff_print().extruders().size() == 1;
+        m_slider->SetManipulationState(m_extruder_selector->GetSelection()==0 ?
+                                       DoubleSlider::msMultiExtruderWholePrint : DoubleSlider::msMultiExtruder);
     }
+    else
+        m_slider->SetManipulationState(DoubleSlider::msSingleExtruder);
+
 }
 //  #ys_FIXME_COLOR
 void Preview::check_slider_values(std::vector<double>& ticks_from_config,
diff --git a/src/slic3r/GUI/GUI_Preview.hpp b/src/slic3r/GUI/GUI_Preview.hpp
index 551900277..574f827e2 100644
--- a/src/slic3r/GUI/GUI_Preview.hpp
+++ b/src/slic3r/GUI/GUI_Preview.hpp
@@ -103,6 +103,7 @@ class Preview : public wxPanel
     bool m_enabled;
 
     DoubleSlider* m_slider {nullptr};
+    wxComboBox*   m_extruder_selector {nullptr};
 
 public:
     Preview(wxWindow* parent, Bed3D& bed, Camera& camera, GLToolbar& view_toolbar, Model* model, DynamicPrintConfig* config, 
@@ -129,7 +130,8 @@ public:
     void move_double_slider(wxKeyEvent& evt);
     void edit_double_slider(wxKeyEvent& evt);
 
-    void update_view_type();
+    void update_view_type(bool slice_completed);
+    void update_extruder_selector();
 
     bool is_loaded() const { return m_loaded; }
 
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 96af17999..477a0b242 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -4702,7 +4702,7 @@ void Plater::reslice()
         p->show_action_buttons(true);
 
     // update type of preview
-    p->preview->update_view_type();
+    p->preview->update_view_type(true);
 }
 
 void Plater::reslice_SLA_supports(const ModelObject &object, bool postpone_error_messages)
diff --git a/src/slic3r/GUI/wxExtensions.cpp b/src/slic3r/GUI/wxExtensions.cpp
index e6e569939..e9f5ac329 100644
--- a/src/slic3r/GUI/wxExtensions.cpp
+++ b/src/slic3r/GUI/wxExtensions.cpp
@@ -3056,8 +3056,8 @@ wxString DoubleSlider::get_tooltip(bool is_revert_icon_focused)
         tooltip = tick_code_it == m_ticks_.end()            ? _(L("Add color change")) :
                   tick_code_it->gcode == "M600"             ? _(L("Delete color change")) :
                   tick_code_it->gcode == "M25"              ? _(L("Delete pause")) :
-                  tick_code_it->gcode == "tool_change"      ? 
-                  from_u8((boost::format(_utf8(L("Delete extruder change to \"%1%\""))) % tick_code_it->extruder).str()) :
+                  tick_code_it->gcode == "tool_change"      ? ( m_state == msSingleExtruder ? _(L("Delete color change")) :
+                  from_u8((boost::format(_utf8(L("Delete extruder change to \"%1%\""))) % tick_code_it->extruder).str()) ) :
                   from_u8((boost::format(_utf8(L("Delete \"%1%\" code"))) % tick_code_it->gcode).str());
     }
 
@@ -3329,7 +3329,7 @@ void DoubleSlider::OnRightUp(wxMouseEvent& event)
     if (m_show_context_menu) {
         wxMenu menu;
 
-        if (m_state == msMultiExtruderSimple)
+        if (m_state == msMultiExtruderWholePrint)
         {
             const wxString name = _(L("Change extruder"));
 
@@ -3349,9 +3349,8 @@ void DoubleSlider::OnRightUp(wxMouseEvent& event)
                 menu.AppendSubMenu(change_extruder_menu, name, _(L("Use another extruder")));
             }
         }
-
-        if (m_state != msMultiExtruderSimple)
-        append_menu_item(&menu, wxID_ANY, _(L("Add color change")) + " (M600)", "",
+        else
+            append_menu_item(&menu, wxID_ANY, _(L("Add color change")) + " (M600)", "",
             [this](wxCommandEvent&) { add_code("M600"); }, "colorchange_add_off.png", &menu);
     
         append_menu_item(&menu, wxID_ANY, _(L("Add pause SD print")) + " (M25)", "",
@@ -3382,16 +3381,17 @@ void DoubleSlider::add_code(std::string code)
             wxString msg_header = from_u8((boost::format(_utf8(L("Custom Gcode on current layer (%1% mm)."))) % m_values[tick]).str());
 
             // get custom gcode
-            wxTextEntryDialog dlg(nullptr, msg_text, msg_header, wxEmptyString, 
+            wxTextEntryDialog dlg(nullptr, msg_text, msg_header, m_custom_gcode,
                                   wxTextEntryDialogStyle | wxTE_MULTILINE);
             if (dlg.ShowModal() != wxID_OK || dlg.GetValue().IsEmpty())
                 return;
 
-            code = dlg.GetValue().c_str();
+            m_custom_gcode = dlg.GetValue();
+            code = m_custom_gcode.c_str();
         }
 
         int extruder = 0;
-        if (m_state == msMultiExtruderSimple)
+        if (m_state == msMultiExtruderWholePrint)
             extruder = get_extruder_for_tick(m_selection == ssLower ? m_lower_value : m_higher_value);
 
         m_ticks_.insert(TICK_CODE(tick, code, extruder));
diff --git a/src/slic3r/GUI/wxExtensions.hpp b/src/slic3r/GUI/wxExtensions.hpp
index e874dbf38..b7fd81db3 100644
--- a/src/slic3r/GUI/wxExtensions.hpp
+++ b/src/slic3r/GUI/wxExtensions.hpp
@@ -809,7 +809,7 @@ public:
     static enum ManipulationState {
         msSingleExtruder,           // single extruder printer preset is selected
         msMultiExtruder,            // multiple extruder printer preset is selected
-        msMultiExtruderSimple       // multiple extruder printer preset is selected, but one-extruder print is detected 
+        msMultiExtruderWholePrint   // multiple extruder printer preset is selected, and "Whole print" is selected 
     };
     void SetManipulationState(ManipulationState state) {
         m_state = state;
@@ -903,6 +903,7 @@ private:
     bool        m_is_enabled_tick_manipulation = true;
     bool        m_show_context_menu = false;
     ManipulationState m_state = msSingleExtruder;
+    wxString    m_custom_gcode = wxEmptyString;
 
     wxRect      m_rect_lower_thumb;
     wxRect      m_rect_higher_thumb;