Of all the composition elements we work with, color fascinates yet baffles students of art more than any of the others. And I would go so far as to say that among those teaching painting, there is more dogma about color than about all the other visual elements combined. In fact, I suspect the prevailing dogmatic teachings are largely responsible for the student artists' fear of color. My personal opinion is that we all should be wary of dogma. Any school of thought claiming to be the only way should be suspect.
It seems to me that the best way to understand color is to work with it and watch what happens. As a beginning, I offer here one way master artists have learned to work with color:
Experience making color:
Begin with one dark and one light and explore possible changes that can happen in sequence from dark to light. Here's an example of what can happen to Rembrandt Raw Umber and Utrecht Hansa Yellow Light.
Here's another with Utrecht Permanent Alizarin Crimson and Rembrandt Cadmium Yellow Deep.
How about this one: Ivory black and Utrecht Hansa Yellow Light.
Here's a fun pair: Gamblin Cadmium Red Light with Rembrandt Viridian at the top and with Utrecht Thalo Yellow Green on bottom.
If you do this little exercise with all your favorite tube colors, you will experience working with color and through that experience, you will obtained a working knowledge. And you can gain additional experience by creating value lines with your mixtures using white...
...like this.
This little experiencing exercise can be taken as far as you like. There are no rules and no limits to what you can discover. And the best part is that there is no dogma you feel you must follow.