Thanks, this behaviour is actually by design. The toolbar bitmaps in mIRC use $rgb(255,0,255) as the transparency color, this is why the alpha channel pixels are tinted pink in this case. You can reproduce this in @windows using /drawpic -t with $rgb(255,0,255). One solution would be to add a /toolbar switch that loads the bitmap without $rgb(255,0,255) as the transparency color. I have added this to my to-do list.