You have to edit color palette, if you want to use another color on gunsight. Windows Paingbrush can't edit color palette...I think, so I use Paint Shop Pro to create new gunsight. Palatte No.255 is the transparent color, so we can use another palatte.
If you don't have a proper paint tool, create new file on Paintbrush, resize to the apropriate size(ie 32x32,64x64,128x128...) and paint the background white. The default transparent color(palatte No.255) is white.
thank you.