Emerald Saber Rainbow Color Cycle

So I was playing around with my emerald saber as one does on a Saturday morning when work doesn't sound appealing when I decided to plug it in to change colors. I am aware that it can make three colors easily' set one to produce pure blue light and the other to produce pure red light and you get a purple in the middle. I then wondered "Can it rainbow?" I have some experience with mixing color, as I do logo design part time. You could do it easily with three color presets; set each one to R G and B respectively and it would make a perfect rainbow as it transitions in between the colors. Spacing considerations and timing aside, it would come out pretty well, I think.

I tried several different things, but none worked out terribly well. I can get it do do a psuedo-CMY cycle by setting one to orange (about 20% G, 100% R)(I know not yellow) and the other to a blue-cyan (about 50% G, 100% B). That way as it transitions it makes a magenta briefly before transitioning into bluer light. The offset green is done so that it does not ever produce an even mixture of RGB light. Even at that, it is not ideal, as there is no way to control the rate of change in the diodes as they transition between colors. The most I can get is three colors.

Now, does anyone know if it is possible to do something tricky so that the saber cycles through all of the colors, given the two color preset? If not, which I suspect is the case, does anyone know if it is at all possible to modify the board or the program so a third color setting can come up?

Best,
Dersee