With Halloween around the corner I'm sure you could find all kinds of temporary hair color, paint & glitter.
Braided mane with pink ribbons braided through
You could make awareness signs or paint them on her hindquarters, my fave is "Save the tatas, Have your mammies gramed"
Definitely share pics, sounds like a fun time & a great cause!
Life is like a camera. Focus on what's important, Capture the good times, Develop from the negatives and if things don't work out, Take another shot.