For a few years I have wanted to create a video tutorial series about color as it pertains to digital painters, and particularly the problem of composition. I finally decided to do it a few weeks ago and the result is 10 videos (a bit over an hour) of what I would consider to be some of the most fundamental things painters need to understand to wield color effectively.
I tried to keep it as simple as possible and minimize side trips into technical details that, while interesting, are ultimately information overkill for most artists. What this series mostly focuses on is contrast, and how it is present in all three color attributes (Hue, Saturation and Value). Once I have established the basic concepts of what the three attributes actually are and how we define (and control) contrast for each, I use some well known example artwork to show the principles in action.
I consider this stuff to be very basic to creating good paintings, and would expect a lot of other artists to think so too. Hopefully you find these videos helpful... if you do, please pass the link along.