I used some crayola washable paint, but a couple globs in quart size ziploc baggies, then taped it down to these trays they use to keep their activities in one spot (my mom brought these to me from the Dollar store in the states).
Now, get out cookie cutters, paint brushes, rolling pin... Anything you have... And let their creativity begin!
globs of paint
put them to work
of course little man needed to try out his cars
they thought it was SO interesting when the paint mixed together to create new colors!