At last, a solution to the brush problem! I bought "color fill" and a short, wide glass container at Michaels for less than $12. Works great for keeping them standing up.
The big face brushes in the tall plastic container: The container was $1 at the Dollar Store, and I filled it with 3 bags of fishtank stones of different colors. It's sort of hard to shove the brush ends into the stones, but it holds steady once they are in!