Bartosz Kosiorek (@gang65) commented about dlls/gdiplus/tests/image.c:
/* color icon 1 bit */ hbmMask = CreateBitmap(16, 16, 1, 1, bmp_bits); ok(hbmMask != 0, "CreateBitmap failed\n"); hbmColor = CreateBitmap(16, 16, 1, 1, bmp_bits);
`bmp_bits` is never initialized, which usually means it is filled with zeros. I would recommend to use different values for mask and for Color, to have more real life scenario.