when a window has focus, the button looks ok (winxp, with chrome style)
but when a window is deselected, the button background correctly fades to a light color, but the image does not,
it stays solid black.

(beta 12)

most of the images (about 90%) are one or 2 colors only,
so it should be possible to define those colors as colorkey, and replace those colors with lighter colors when de-focused?

optionally, and more generally, it should also be possible to make a copy from the image in memory, and make it a bit lighter.

ps: if you resolve the window message only at dll injection, and cache the result, it might speed up the postmessage slightly
(not having to resolve the string to unique window message on each mouse event)

if you don't mind an extra option, you could make a slider to control how much its made lighter.