Color has always been tough for me… I tend to use analogous color schemes — like yellow-green, green and green-blue, so I can avoid the entire issue!
But I spent quite a bit of time learning – once you can pair value (how light or dark an area is) with color-brightness and contrast, and complimentary colors, the world opens up. I play with all of this in paint first these days – no intention of creating finished or resolved work from them, just little experiments in what works and why, and my color choices in threads need to be ripped out much less now, although I have discovered that what works in thread on a small scale may not work when enlarged — for example, three colors that work as a small face don’t necessarily work together when enlarged to an 8 1/2 by 11 inch piece of work. This seems to happen more in thread than in paint for me, at least right now. Still working that out.
I’ve been trying to learn this academically for a long while now – but the more I read, or even pushed buttons for (online resources follow) the less I understood. It finally took getting a bunch of cheap acrylic paint and doing it myself to actually grok it. My experiments may be ugly, but they did what they were intended to do! (I used quite a few of them as backgrounds in my journal, or I’d post more of the photos here.)
There are many interesting books on the subject (“Yellow and Blue Don’t Make Green” was one), but like you I find playing with paint or crayons far more useful.
Finally, if you want to see rules being broken, go out into the countryside and look at a few sunsets!
Nature is my great source for inspiration! What I am finding is that things I can do with paint, crayons or pencils is a little different in thread. I’ve got a wonderful book on color for embroiderers (Color for Embroidery by Mary Shipp: I’ve never purchased from the store in that link…) if you REALLY want to get involved in the theory. Yellow and Blue Don’t Make Green is also very good.