Demo: custom rendering example uses AddRectFilledMultiColor()

imgui.cpp

@@ -12272,7 +12272,8 @@ static void ShowExampleAppCustomRendering(bool* opened)
     // If you only use the ImDrawList API, you can notify the owner window of its extends by using SetCursorPos(max).
     ImVec2 canvas_pos = ImGui::GetCursorScreenPos();            // ImDrawList API uses screen coordinates!
     ImVec2 canvas_size = ImVec2(ImMax(50.0f,ImGui::GetWindowContentRegionMax().x-ImGui::GetCursorPos().x), ImMax(50.0f,ImGui::GetWindowContentRegionMax().y-ImGui::GetCursorPos().y));    // Resize canvas what's available
-    draw_list->AddRect(canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), 0xFFFFFFFF);
+    draw_list->AddRectFilledMultiColor(canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), ImColor(0,0,0), ImColor(255,0,0), ImColor(255,255,0), ImColor(0,255,0));
+    draw_list->AddRect(canvas_pos, ImVec2(canvas_pos.x + canvas_size.x, canvas_pos.y + canvas_size.y), ImColor(255,255,255));
     bool adding_preview = false;
     ImGui::InvisibleButton("canvas", canvas_size);
     if (ImGui::IsItemHovered())