My son loves oatmeal, but he especially loves oatmeal if it is purple (or blue, or orange...). I have noticed that when I add food coloring to food, my kids get really excited about eating it. So these pictures may look absolutely disgusting to you, but to my 5 year old they are a little bit of heaven.
We have talked about how mixing red and blue make purple, red and yellow make orange, etc. So that's a learning experience in and of itself. Oh, we also swirl food coloring into pancakes. We just put 5 or 6 drops in the batter at the very end, and stir two or three times (mix it any more and the pancakes just look dirty, not colorful). We have also done all things green on St. Patrick's Day, and all things yellow on a theme dinner night. Food coloring is pretty awesome. What do you add it to?