diff --git a/upptst/InvertColor/InvertColor.upp b/upptst/InvertColor/InvertColor.upp
new file mode 100644
index 000000000..5872304d3
--- /dev/null
+++ b/upptst/InvertColor/InvertColor.upp
@@ -0,0 +1,9 @@
+uses
+	CtrlLib;
+
+file
+	main.cpp;
+
+mainconfig
+	"" = "GUI";
+
diff --git a/upptst/InvertColor/main.cpp b/upptst/InvertColor/main.cpp
new file mode 100644
index 000000000..bcdbb1ee2
--- /dev/null
+++ b/upptst/InvertColor/main.cpp
@@ -0,0 +1,23 @@
+#include <CtrlLib/CtrlLib.h>
+
+using namespace Upp;
+
+struct MyApp : TopWindow {
+	virtual void Paint(Draw& w) {
+		w.DrawRect(GetSize(), White());
+		
+		for(Color c : { Black(), Blue(), Red(), Yellow() }) {
+			w.DrawRect(10, 10, 200, 100, c);
+			w.DrawRect(30, 30, 50, 50, InvertColor());
+	
+			w.DrawRect(130, 30, 50, 50, InvertColor());
+			w.DrawRect(150, 30, 50, 50, InvertColor());
+			w.Offset(0, 120);
+		}
+	}
+};
+
+GUI_APP_MAIN
+{
+	MyApp().Run();
+}