The earliest palettes were made rectangular in shape and date back to 5000 BC later pallets adopted a rounder shape, using the Narmer paletteNarmer Palette, reverse side; Source: The Glory of Egypt by Samivel, 1955
Even later palettes took the shape of a fish, and then morphed into a baboon shaped container. Tombs have been found with both shapes of cosmetic palettes buried with the deceased as