The mechanic works well with modern paintings and with simple shapes, but doesn't work when there are colour transitions. An example of this would be the Magritte - La voix des airs painting. I couldn't figure out which colour each square needed to be.
Yes, we figured this out ! It's a nice LD lesson about shapes/colors and recognition capacity. As a level designer I didn't think this would be a problem, but as a matter of fact, a lot of people experienced unfair difficulties with the Magritte !
Thanks for playing :)