I got confused at first because I didn’t know about that Sanderson book series and thought you were talking about The Lightbringer Series by Brent Weeks. They develop colored rings based upon the light spectrums they use, each with their own properties. Their nobility or such being those who use multiple colors and usually their is one Prism, who can use the full spectrum of light. (It touches on a couple outside out view like sub red and ultraviolet as well)