Did some work on the red and black area. The green and yellow has to dry a bit more before I’m going to do anything with it. When I woke up this morning, I thought the lower center-left area of the red thing was too bright, so I darkened it up a bit. Photos below.
The green and yellow area is pretty lucky, as it is only those two colors, and it’s pretty easy to blend two pretty compatible colors. That’s why the next step may utterly destroy the work: adding black and white for shadows and highlights.
(As always, when I say “black” I mean “raw umber.”)