I found that game super hard ! My mother is a painter and history of art teacher, i feel like she'd do better than me XD
I found some details and patterns though, to get some paints right, like the shape of the head.
I think it'd be more interesting if you wrote some notes, like when you get a paint right, you have a tip on what you can look after in the other pictures, in relation with the one you found. Not sure if i explain well.