This free printable preschool color mixing early learning pack for preschoolers is a great way to introduce young kids to color mixing. My kids had a blast discovering what colors would be made by mixing two paints together.
Learn how to spell the colors with these jazzy little jingles (from the Color Songs CD by Frog Street Press). My son's PreK teacher uses these! Kids learn how to spell their color words very easily when they learn it in a song.