https://bugs.winehq.org/show_bug.cgi?id=44392
--- Comment #10 from Nikolay Sivov bunglehead@gmail.com --- We now have separate implementation in comctl32/button.c, so this issue is fixable with current wine. My guess is that for certain bitmaps it picks transparent color from (0,0) or something similar. That also means we'll have to use something other than DrawState() to handle this, because it does not support transparency.