ColorButton: As a small convenience, provide a text baseline.

imgui.cpp

@@ -9419,7 +9419,7 @@ bool ImGui::ColorButton(const char* desc_id, const ImVec4& col, ImGuiColorEditFl
     if (size.y == 0.0f)
         size.y = default_size;
     const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size);
-    ItemSize(bb);
+    ItemSize(bb, (size.y >= default_size) ? g.Style.FramePadding.y : 0.0f);
     if (!ItemAdd(bb, id))
         return false;