When we did the food coloring experiment (here), we froze the water in ice cube trays afterwards, but it wasn't any good for consumption, what with bits of paper towel and dust from being left out over night.
I saw the lovely pin linked above, where you can read about her boy painting afterwards as part of the lesson. But, see, the last experiment was so much work compared to how much my boy got out of it. I mean, he's only three years old. So one day when the kids were in the bath, I had an idea.
|Bathtub + ice cubes + white plastic bowl = no mess.|