Cover the fun foam and card with a layer of gesso, let dry. Then paint over the whole thing with acrylic paint color of your choice and let dry.
Bernie suggests using quick-drying pigment ink for the next step. I've been wanting to use this copper StazOn ink I picked up. I created my own ink pad by using a piece of cut n dry foam. Used a large script stamp to stamp the copper ink over the foam and card and let dry.
I really liked how this turned out: