I used Magic Watercolors, liquid paint.
We just dropped them in beginning with yellow then 2 blues and black.
We took a feather and swirled. The paper was simple typing paper and we
very gently rubbed with our fingers after laying it on the shaving cream. The
colors actually colored through the paper.
Some of the back prints were as nice as the front. But most were just the
Then we let them dry a couple of days without disturbing (probably sooner is
and brushed off the shaving cream remnant with a wadded up paper towel.