diff --git a/Framework/GUISupport/src/FrameworkGUIDevicesGraph.cxx b/Framework/GUISupport/src/FrameworkGUIDevicesGraph.cxx
index 1c4ddd7e6aabf..eeb9aeb44795e 100644
--- a/Framework/GUISupport/src/FrameworkGUIDevicesGraph.cxx
+++ b/Framework/GUISupport/src/FrameworkGUIDevicesGraph.cxx
@@ -41,8 +41,37 @@ struct NodeColor {
 
 using LogLevel = LogParsingHelpers::LogLevel;
 
-NodeColor decideColorForNode(const DeviceInfo& info)
+NodeColor decideColorForNode(const DeviceInfo& info, bool lightMode)
 {
+  if (lightMode) {
+    // Dark-on-bright: rich medium-dark cards on a white canvas, white text on nodes
+    if (info.active == false) {
+      return NodeColor{
+        .normal = ImVec4(0xb5 / 255.f, 0x26 / 255.f, 0x18 / 255.f, 1), // dark crimson
+        .hovered = ImVec4(0xc2 / 255.f, 0x2d / 255.f, 0x1d / 255.f, 1)};
+    }
+    switch (info.streamingState) {
+      case StreamingState::EndOfStreaming:
+        return NodeColor{
+          .normal = ImVec4(0x8c / 255.f, 0x6c / 255.f, 0x00 / 255.f, 1), // dark amber
+          .hovered = ImVec4(0x9e / 255.f, 0x7a / 255.f, 0x00 / 255.f, 1),
+          .title = ImVec4(0x6e / 255.f, 0x54 / 255.f, 0x00 / 255.f, 1),
+          .title_hovered = ImVec4(0x5a / 255.f, 0x44 / 255.f, 0x00 / 255.f, 1)};
+      case StreamingState::Idle:
+        return NodeColor{
+          .normal = ImVec4(0x1a / 255.f, 0x80 / 255.f, 0x40 / 255.f, 1), // dark forest green
+          .hovered = ImVec4(0x22 / 255.f, 0x8b / 255.f, 0x47 / 255.f, 1),
+          .title = ImVec4(0x11 / 255.f, 0x60 / 255.f, 0x2e / 255.f, 1),
+          .title_hovered = ImVec4(0x0a / 255.f, 0x4d / 255.f, 0x23 / 255.f, 1)};
+      case StreamingState::Streaming:
+      default:
+        return NodeColor{
+          .normal = ImVec4(0x3a / 255.f, 0x3a / 255.f, 0x3c / 255.f, 1), // macOS tertiary dark
+          .hovered = ImVec4(0x48 / 255.f, 0x48 / 255.f, 0x4a / 255.f, 1),
+          .title = ImVec4(0x2c / 255.f, 0x2c / 255.f, 0x2e / 255.f, 1),
+          .title_hovered = ImVec4(0x1c / 255.f, 0x1c / 255.f, 0x1e / 255.f, 1)};
+    }
+  }
   if (info.active == false) {
     return NodeColor{
       .normal = PaletteHelpers::RED,
@@ -82,7 +111,7 @@ const static ImColor ARROW_BACKGROUND_COLOR = {100, 100, 0};
 const static ImColor ARROW_HALFGROUND_COLOR = {170, 170, 70};
 const static ImColor ARROW_COLOR = {200, 200, 100};
 const static ImColor ARROW_SELECTED_COLOR = {200, 0, 100};
-const static ImU32 GRID_COLOR = ImColor(200, 200, 200, 40);
+const static ImU32 GRID_COLOR = ImColor(150, 150, 150, 80);
 const static ImColor NODE_BORDER_COLOR = {100, 100, 100};
 const static ImColor LEGEND_COLOR = {100, 100, 100};
 
@@ -508,6 +537,8 @@ void showTopologyNodeGraph(WorkspaceGUIState& state,
   ImGui::SameLine();
   ImGui::Checkbox("Show legend", &show_legend);
   ImGui::SameLine();
+  ImGui::Checkbox("Light mode", &state.topologyLightMode);
+  ImGui::SameLine();
   if (ImGui::Button("Center")) {
     scrolling = ImVec2(0., 0.);
   }
@@ -577,11 +608,10 @@ void showTopologyNodeGraph(WorkspaceGUIState& state,
 
   ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(1, 1));
   ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0, 0));
-#if defined(ImGuiCol_ChildWindowBg)
-  ImGui::PushStyleColor(ImGuiCol_ChildWindowBg, (ImU32)ImColor(60, 60, 70, 200));
-#else
-  ImGui::PushStyleColor(ImGuiCol_WindowBg, (ImU32)ImColor(60, 60, 70, 200));
-#endif
+  auto canvasBg = state.topologyLightMode ? (ImU32)ImColor(250, 250, 252, 255) : (ImU32)ImColor(44, 44, 46, 255);
+  auto canvasText = (ImU32)ImColor(235, 235, 245, 255); // nodes are always dark, so text is always light
+  ImGui::PushStyleColor(ImGuiCol_ChildBg, canvasBg);
+  ImGui::PushStyleColor(ImGuiCol_Text, canvasText);
   ImVec2 graphSize = ImGui::GetWindowSize();
   if (state.leftPaneVisible) {
     graphSize.x -= state.leftPaneSize;
@@ -604,6 +634,12 @@ void showTopologyNodeGraph(WorkspaceGUIState& state,
 
   ImVec2 win_pos = ImGui::GetCursorScreenPos();
   ImVec2 canvas_sz = ImGui::GetWindowSize();
+
+  // Arrow colors — richer amber in light mode to stand out on white canvas
+  const ImColor arrowBgColor = state.topologyLightMode ? ImColor(140, 80, 0) : ARROW_BACKGROUND_COLOR;
+  const ImColor arrowHalfColor = state.topologyLightMode ? ImColor(180, 110, 0) : ARROW_HALFGROUND_COLOR;
+  const ImColor arrowColor = state.topologyLightMode ? ImColor(220, 140, 0) : ARROW_COLOR;
+
   // Display links but only if they are inside the view.
   for (int link_idx = 0; link_idx < links.Size; link_idx++) {
     // Do the geometry culling upfront.
@@ -627,7 +663,7 @@ void showTopologyNodeGraph(WorkspaceGUIState& state,
       continue;
     }
     draw_list->ChannelsSetCurrent(0); // Background
-    auto color = ARROW_BACKGROUND_COLOR;
+    auto color = arrowBgColor;
     auto thickness = ARROW_BACKGROUND_THICKNESS;
 
     bool p1Inside = false;
@@ -643,12 +679,12 @@ void showTopologyNodeGraph(WorkspaceGUIState& state,
     if (p1Inside && p2Inside) {
       // Whatever the two edges completely within the view, gets brighter color and foreground.
       draw_list->ChannelsSetCurrent(2);
-      color = ARROW_COLOR;
+      color = arrowColor;
       thickness = ARROW_THICKNESS;
     } else if (p1Inside || p2Inside) {
       draw_list->ChannelsSetCurrent(1);
       // Whenever one of the two ends is within the view, increase the color but keep the background
-      color = ARROW_HALFGROUND_COLOR;
+      color = arrowHalfColor;
       thickness = ARROW_HALFGROUND_THICKNESS;
     }
 
@@ -756,7 +792,7 @@ void showTopologyNodeGraph(WorkspaceGUIState& state,
       scrolling = scrolling - ImVec2(ImGui::GetIO().MouseDelta.x / 4.f, ImGui::GetIO().MouseDelta.y / 4.f);
     }
 
-    auto nodeBg = decideColorForNode(info);
+    auto nodeBg = decideColorForNode(info, state.topologyLightMode);
 
     auto hovered = (node_hovered_in_list == node->ID || node_hovered_in_scene == node->ID || (node_hovered_in_list == -1 && node_selected == node->ID));
     ImVec4 nodeBgColor = hovered ? nodeBg.hovered : nodeBg.normal;
@@ -776,7 +812,7 @@ void showTopologyNodeGraph(WorkspaceGUIState& state,
       auto pp1 = p1 + offset + slotPos;
       auto pp2 = p2 + offset + slotPos;
       auto pp3 = p3 + offset + slotPos;
-      auto color = ARROW_COLOR;
+      auto color = arrowColor;
       if (node_idx == node_selected) {
         color = ARROW_SELECTED_COLOR;
       }
@@ -881,7 +917,7 @@ void showTopologyNodeGraph(WorkspaceGUIState& state,
 
   ImGui::PopItemWidth();
   ImGui::EndChild();
-  ImGui::PopStyleColor();
+  ImGui::PopStyleColor(2);
   ImGui::PopStyleVar(2);
   ImGui::EndGroup();
 
diff --git a/Framework/GUISupport/src/FrameworkGUIState.h b/Framework/GUISupport/src/FrameworkGUIState.h
index 8a1cd8dd3bd1e..d36b6c6120fc0 100644
--- a/Framework/GUISupport/src/FrameworkGUIState.h
+++ b/Framework/GUISupport/src/FrameworkGUIState.h
@@ -34,6 +34,7 @@ struct WorkspaceGUIState {
   bool leftPaneVisible;
   bool rightPaneVisible;
   bool bottomPaneVisible;
+  bool topologyLightMode;
   double startTime;
 };
 
diff --git a/Framework/GUISupport/src/PaletteHelpers.cxx b/Framework/GUISupport/src/PaletteHelpers.cxx
index 1ad04ce7c7f3f..fa19b0dd43319 100644
--- a/Framework/GUISupport/src/PaletteHelpers.cxx
+++ b/Framework/GUISupport/src/PaletteHelpers.cxx
@@ -13,20 +13,35 @@
 namespace o2::framework
 {
 
-const ImVec4 PaletteHelpers::RED = ImVec4(0.945, 0.094, 0.298, 1);
-const ImVec4 PaletteHelpers::GREEN = ImVec4(0x7e / 255., 0xc4 / 255., 0x52 / 255., 1);
-const ImVec4 PaletteHelpers::BLUE = ImVec4(0x3d / 255., 0xb7 / 255., 0xe0 / 255., 1);
-const ImVec4 PaletteHelpers::YELLOW = ImVec4(0.949, 0.769, 0.239, 1);
-const ImVec4 PaletteHelpers::SHADED_RED = ImVec4(0xd5 / 255., 0x72 / 255., 0x73 / 255., 1);
-const ImVec4 PaletteHelpers::SHADED_GREEN = ImVec4(0x98 / 255., 0xba / 255., 0x96 / 255., 1);
-const ImVec4 PaletteHelpers::SHADED_BLUE = ImVec4(0x7a / 255., 0xab / 255., 0xea / 255., 1);
-const ImVec4 PaletteHelpers::SHADED_YELLOW = ImVec4(0xeb / 255., 0xb9 / 255., 0x7a / 255., 1);
-const ImVec4 PaletteHelpers::DARK_RED = ImVec4(0xd4 / 255., 0x06 / 255., 0x02 / 255., 255. / 255.);
-const ImVec4 PaletteHelpers::DARK_GREEN = ImVec4(153. / 255., 61. / 255., 61. / 255., 255. / 255.);
-const ImVec4 PaletteHelpers::DARK_YELLOW = ImVec4(0xf1 / 255., 0x9b / 255., 0x2c / 255., 255. / 255.);
-const ImVec4 PaletteHelpers::WHITE = ImVec4(0xce / 255., 0xbe / 255., 0x91 / 255., 1);
-const ImVec4 PaletteHelpers::BLACK = ImVec4(0x28 / 255., 0x28 / 255., 0x28 / 255., 1);
-const ImVec4 PaletteHelpers::GRAY = ImVec4(60 / 255., 60 / 255., 60 / 255., 1);
-const ImVec4 PaletteHelpers::LIGHT_GRAY = ImVec4(75 / 255., 75 / 255., 75 / 255., 1);
+// Vivid accent colors — macOS system color palette / Pantone-adjacent
+// RED: macOS Red (#FF3B30) / Pantone 485 C adjacent
+const ImVec4 PaletteHelpers::RED = ImVec4(0xff / 255., 0x3b / 255., 0x30 / 255., 1);
+// GREEN: macOS Green (#34C759) / Pantone 368 C adjacent
+const ImVec4 PaletteHelpers::GREEN = ImVec4(0x34 / 255., 0xc7 / 255., 0x59 / 255., 1);
+// BLUE: macOS Blue (#007AFF) / Pantone 2728 C adjacent
+const ImVec4 PaletteHelpers::BLUE = ImVec4(0x00 / 255., 0x7a / 255., 0xff / 255., 1);
+// YELLOW: macOS Yellow (#FFCC00) / Pantone 116 C adjacent
+const ImVec4 PaletteHelpers::YELLOW = ImVec4(0xff / 255., 0xcc / 255., 0x00 / 255., 1);
+// Muted/shaded variants — desaturated for secondary use
+const ImVec4 PaletteHelpers::SHADED_RED = ImVec4(0xff / 255., 0x69 / 255., 0x61 / 255., 1);
+const ImVec4 PaletteHelpers::SHADED_GREEN = ImVec4(0x86 / 255., 0xd9 / 255., 0x88 / 255., 1);
+const ImVec4 PaletteHelpers::SHADED_BLUE = ImVec4(0x5a / 255., 0xc8 / 255., 0xfa / 255., 1);
+const ImVec4 PaletteHelpers::SHADED_YELLOW = ImVec4(0xff / 255., 0xd6 / 255., 0x0a / 255., 1);
+// Dark variants — for title bars and hovered states
+// DARK_RED: Pantone 485 C (#DA291C)
+const ImVec4 PaletteHelpers::DARK_RED = ImVec4(0xda / 255., 0x29 / 255., 0x1c / 255., 1);
+// DARK_GREEN: (#1E8449)
+const ImVec4 PaletteHelpers::DARK_GREEN = ImVec4(0x1e / 255., 0x84 / 255., 0x49 / 255., 1);
+// DARK_YELLOW: macOS Orange (#FF9F0A) / Pantone 137 C adjacent
+const ImVec4 PaletteHelpers::DARK_YELLOW = ImVec4(0xff / 255., 0x9f / 255., 0x0a / 255., 1);
+// Neutrals — macOS dark mode system backgrounds
+// WHITE: used as primary text / highlight color in dark UI
+const ImVec4 PaletteHelpers::WHITE = ImVec4(0xf5 / 255., 0xf5 / 255., 0xf7 / 255., 1);
+// BLACK: macOS dark background (#1C1C1E)
+const ImVec4 PaletteHelpers::BLACK = ImVec4(0x1c / 255., 0x1c / 255., 0x1e / 255., 1);
+// GRAY: macOS secondary background (#2C2C2E)
+const ImVec4 PaletteHelpers::GRAY = ImVec4(0x2c / 255., 0x2c / 255., 0x2e / 255., 1);
+// LIGHT_GRAY: macOS tertiary background (#3A3A3C)
+const ImVec4 PaletteHelpers::LIGHT_GRAY = ImVec4(0x3a / 255., 0x3a / 255., 0x3c / 255., 1);
 
 } // namespace o2::framework