Oil of wintergreen works with color copies from kinko's...
make color copy, place on paper with image side down, apply oil of
wintergreen to back of copy and run through press.
I have used this method several times and like the end result very much.
Some of the problems I have had with this method is that it seems to only
work with color copies from Kinko's and that you have to find a drug store
that carries oil of wintergreen.