It’s best to color him yellow since he never changes color.
You just need to color the mouth red or pink.
The best way is to color the mouth a dark red, and the tongue pink.
Finish the outline by darkening it.
Jake’s eyes are black with a big white reflection.
Make sure when you darken to leave the white reflections in the eyes untouched.
Both eyes have the same reflections.
Now, add the final touches to finish your Jake drawing.