I had Hailey squeeze the food coloring on the different piles and stir with her fingers.
Hailey doesn't like being messy so she enjoyed watching (and telling) me what to do. We "drew" a flower, the letter H for Hailey, and the letter Y in the yogurt. She also ate some especially the blue colored one. (We used vanilla yogurt.)
I couldn't think of any books to go along with this. I didn't want a yellow book since we'll be doing colors soon.