Homemade Finger Paint

My 17 month old son has loved coloring since he was 12 months.  We introduced crayons to him very early and it's been something we do together as a family quite frequently.  He calls it: cah-cah because he can't quite say cah-lah.  We live in New England and the R's are removed from most words so I doubt he'll be pronouncing those for a while. 

We cah-cah a lot.  Almost too much.  I think he enjoys holding the crayons and inspecting them more than he does seeing the color on the paper.  But there are days when he surprises me and he is starting to understand the actual activity of coloring.

Since his perception of coloring has evolved over the past few weeks, I thought I'd give finger painting a try.  J still likes to put anything and everything into his mouth so I opted to make my own finger paint.  At least if he swallows a finger full of finger paint, it's only full of corn starch.  I'm not very crafty but the recipe seemed easy.

Boil 3 cups of water
Add 1 cup of corn starch
Stir food coloring as desired

So that's what I did, boil and mix.  But my mixing became clumpy.  Did I mix too quickly?

So I thought, maybe if I add food coloring it would get better?

No matter how much I stirred, smashed, mixed, crushed those little corn starch crumbs, they wouldn't break up into the smooth texture I was expecting.

But did this matter to the expert?  Unfortunately I haven't tested the waters with J yet, but hope to later this week.