diff --git a/tests/conform/test-texture-fbo.c b/tests/conform/test-texture-fbo.c
index b11bde080..958fc2932 100644
--- a/tests/conform/test-texture-fbo.c
+++ b/tests/conform/test-texture-fbo.c
@@ -13,10 +13,10 @@
 static const ClutterColor
 corner_colors[SOURCE_DIVISIONS_X * SOURCE_DIVISIONS_Y] =
   {
-    { 0xff, 0x00, 0x00, 0xff },
-    { 0x00, 0xff, 0x00, 0xff },
-    { 0x00, 0x00, 0xff, 0xff },
-    { 0xff, 0x00, 0xff, 0xff }
+    { 0xff, 0x00, 0x00, 0xff }, /* red top left */
+    { 0x00, 0xff, 0x00, 0xff }, /* green top right */
+    { 0x00, 0x00, 0xff, 0xff }, /* blue bottom left */
+    { 0xff, 0x00, 0xff, 0xff }  /* purple bottom right */
   };
 
 static const ClutterColor stage_color = { 0x0, 0x0, 0x0, 0xff };