diff --git a/src/slic3r/GUI/GCodeViewer.cpp b/src/slic3r/GUI/GCodeViewer.cpp
index f14b114e7f7..27b3bc5b0f0 100644
--- a/src/slic3r/GUI/GCodeViewer.cpp
+++ b/src/slic3r/GUI/GCodeViewer.cpp
@@ -873,8 +873,8 @@ void GCodeViewer::load_as_gcode(const GCodeProcessorResult& gcode_result, const
 
         // collect color print colors
         libvgcode::Palette color_print_colors;
-        color_print_colors.reserve(str_color_print_colors.size());
-        for (const std::string& color : str_color_print_colors) {
+        const std::vector<std::string>& str_colors = str_color_print_colors.empty() ? str_tool_colors : str_color_print_colors;
+        for (const std::string& color : str_colors) {
             color_print_colors.emplace_back(libvgcode::convert(color));
         }
         m_viewer.set_color_print_colors(color_print_colors);
diff --git a/src/slic3r/GUI/LibVGCode/LibVGCodeWrapper.cpp b/src/slic3r/GUI/LibVGCode/LibVGCodeWrapper.cpp
index 23af8231031..87c4abb206c 100644
--- a/src/slic3r/GUI/LibVGCode/LibVGCodeWrapper.cpp
+++ b/src/slic3r/GUI/LibVGCode/LibVGCodeWrapper.cpp
@@ -745,8 +745,9 @@ GCodeInputData convert(const Slic3r::Print& print, const std::vector<std::string
     }
 
     // collect color print colors
-    ret.color_print_colors.reserve(str_color_print_colors.size());
-    for (const std::string& color : str_color_print_colors) {
+    const std::vector<std::string>& str_colors = str_color_print_colors.empty() ? str_tool_colors : str_color_print_colors;
+    ret.color_print_colors.reserve(str_colors.size());
+    for (const std::string& color : str_colors) {
         ret.color_print_colors.emplace_back(convert(color));
     }