I use plain white Corning Corelle plates to mix acrylic paints because
it is white and it cleans up easily. A white base for mixing paints will
not bias the colors while mixing. I also use white ceramic cups for the
brush water because they clean up easily as well, whereas plastic cups
usually end up with at least a slight discoloring. All these items clean up
well in the dishwasher. Be sure to rinse off at least most of the paint
before placing the dish in the dishwasher--otherwise you may end up with
flecks of paint on everything!