color them all the same color, something your not going to use anywhere else on the skin. I usually do a pink.

then after you save it as an 8 bmp file, find the index number of that shade of pink.
now open up notepad and type the index number, then save it as b26wings_a.txt and it will make everything that color transparent.
the noseart "flak bait" is a file called logo.bmp. With this I just save the logo.bmp file in my b26 skin folder and then color it all black, save as greyscale image and save the greyscale as "logo_a.bmp" and everything black becomes transparent.