As far as I know there are an infinite number of colors. That system is analog. Like a circle such is a finite or bounded infinity.
Actually the color wheel is not really a circle. The purple harmonic is a straight line, making it more horseshoe shaped. It is also not linear and three dimensional. 3 dimensional non linear solids, are hard to visualize. Even for people like Newton and Einstein. One really needs to be in the 4th dimension to see it. Like looking at a painting from the edge.
I guess this means there are an infinite number of moon swatch variations possible. Now I want a four dimensional moonswatch. (which really is 5 dimensions with time as the zero placeholder.)