I cover my palette with clear adhesive-backed plastic wrap. (See image below.) When finished, I can peel this cover off leaving my palette fairly clean and white so I can see the next series of colors I will use.
I took to hanging these palette covers on the wall of my studio until they dry. Then I took a few dozen covers and used them in whole, or in part, to create this monumental-sized collage and portrait. I would like to mount this on a large light board to discover the effect of backlighting the colors.