I have decided to proceed with using a numeral system running from 0 to 3. Now I need a way to represent that system. I have come up with these four systems:

I’ve been staring at these columns for over an hour, trying to decide which one is easiest to grasp. The first column was my first idea, but it has one flaw: the 3-version doesn’t contain any of the background color needed to indicate that this is a modifier. The other columns lack this problem. The last column really emphasizes the triangularity concept.
I think it’s time for me to do some outside work, get all hot and sweaty, then return to this problem.
Later
So I spent all day mulling it over and ended up deciding on a completely new set:

I like this set because it lends emphasis to the triangularity concept that I want to underly the entire fantasy.