Joe Paquette in his workshops talks about how it's important to do an inventory of the various skills it takes to be a good artist. To make a list, for example, of things like drawing, value, color, composition, etc., and decide which skills are the best-developed and which ones need more work.
I've been feeling like I could use more work on my understanding of how to use color to make a good painting. Since I don't have the opportunity to take a color class right now, I've been searching for a book I could use for self-study.
This book was exactly what I was looking for. It has short sections of explanation and then useful exercises to do to develop an understanding of different aspects of how to use color.
Here's the author's introduction to the first four assignments:
“The first four assignments are designed to clarify the structure of color. Inverting the natural tendency to put hue first, these studies examine hue and value through the lens of saturation. They begin with the most subtle colors, chromatic grays, and work toward the most saturated: prismatic colors.
“These studies go far beyond the definitions, however. They also reveal ways in which hue, value, and saturation are both independent and interdependent in color mixing and in combination with each other. Most importantly, they demonstrate the visual effect of imposed restrictions in any or all three of the structural factors.”
He then shows an example of how Giorgio Morandi used muted color:
The book answers a lot of questions I've had about color.