These are all from photos. I colour pick the colours from the photos and then just throw them to the study. I use a thick brush and I don't care about detail. I take a bit more than half an hour for each and I wish I could get faster. They're not much. It's almost like painting with numbers I guess. What I'm trying with these is to have a better understanding of how colours work. I already found out some things I didn't know and later I'll try to do some stuff from my imagination having these exercices in mind. Let's see if it works. For now, I'll keep on trying a couple of these per day.