I'm sure other people have already added some of these but here's a few things that work from an intermediate level and up, because a lot of easy to find color theory really drops off way before that (really I think anyone can grasp some of these, but some of it may be more difficult than some beginners will enjoy trying to wrap their heads around because they get more into the building blocks of how to achieve your own understanding of color, rather than the surface level stuff thatโs easy to copy that make up most beginner-friendly tutorials)
Yet another of his (reproduced with permission) - he literally wrote the best book on the subject if anyone wants a longer explanation of this
Cynthia Sheppard's limited palette video - it's a video and she does spend a bit of it with medium-specific information about oil paints but she has a very soothing voice and watching her paint is mesmerizing. While she goes duller rather than brighter with her limited palettes, I really think it helps to keep things simpler and easier to understand, you can always go the opposite direction once you understand the principles
I noticed a few replies in the notes were especially upset by color wheels and common color schemes (like the sets below)
and I hope the above explanations are helpful for understanding why those are often taught as a beginner explanation when theyโre almost unusable for most beginners by being both too simple and also not really successfully bridged through to the higher level stuff. The reality is simply that you do have to haveย the color wheel in some capacity - even just mentally - (and if youโre working traditionally, that means you need to know how to mix colors to make one) but itโs because the goal is to start playing with it and blocking off parts of it!
But once you do that, the struggle becomes as much about how to pick those color schemes and how to keep them working internally. Which is where a lot of the concepts aboutย โwarmโ andย โcoolโ start to come in. Because those are often taught asย โhalf the color wheel is one or the otherโ you canโt really apply it straight from there. In order to apply this stuff successfully, you have to start thinking about the perceived warmth or coolness of colors next to each other to make stranger and more vibrant palettes work.
It may seem irrelevant to talk about values here, when the subject is color, but so much of getting color to work at more advanced levels comes down to controlling your values better and better.
This one by Jon Neimeister:
As you can see in the first value article, keeping the value ranges clear does a lot to let you use different and unexpected colors without distracting the viewers - the contrast between the colors can be controlled by careful value placement, which is the real secret to using unpredictable colors. I think Jon's does a simpler job of explaining how to practice the value ranges from reference.
