One of my favorite parts of the illustration process is the color study.
I used to forego painted color studies, instead relying solely on a digitally rendered study. However, I've found tiny painted studies to be helpful tools before I begin working on a final painting.
While some artists do larger, more detailed studies. I prefer to work tiny to problem solve at this stage. I liken it to doing thumbnails when laying out a preliminary book dummy. (For each study shared below, I've included the full-sized measurements.) Not only does it save paper, but these tiny studies are quick. They allow me to do several potential versions in a short amount of time.
My studies are often quite messy, but I do attempt to be somewhat organized and lay out a test strip of the colors that I'm considering for the piece.
I usually lay out a basic thumbnail of the larger painting and block in the major colors. On the same strip of paper, I will also test different combinations of paint to figure out what works best for the particular piece in question.
When I'm being really organized and taking my time, I label each layer and how it was made.
(paper is roughly 6x5.325", each thumbnail is about 2x1.5")
These studies, though tiny, can still be extremely detailed.
Color studies are invaluable. They can be used to test every part of your painting but on a quick, small, and easy scale.
for testing details, like patterns and plaids,
or they help answer larger questions, like overall palette.