I don't know why someone would have a switch like that on their suit, but it seems science-fictiony and high-tech to have one.
It's a symmetrical (on a color wheel) color scheme. There are names for color schemes like primary, analogus, triadic, quadratic, blah blah blah... HECK! I cain't remember all that! It's easier to just remember to keep the patterns symmetrical on a color wheel.
If the color wheel were a bicycle wheel, then I'm talking about the spokes of the wheel being symmetrical. The amount of spokes isn't as important as their symmetricalness.
The easiest is the "I" shape, which is just 2 opposite colors on the wheel.
The "Y" shape looks good. The 2 arms of the Y can swing out at any angle as long as they swing out symmetrically with each other.
Yellow is the root color, and then flanking the yellow symmetrically on either side is green and orange. His suit is nearing blue which is not a part of this color scheme, but since it's almost white, it doesn't really disrupt anything too badly.
Purple is a safe color to use since it's exactly opposite of the root color yellow, and keeps the symmetrical formation of the color scheme. Actually I could just as easily say purple is the root color and yellow is the opposite. "Root" color doesn't really mean main color; It kind of delineates the centerline of the color scheme spoke arrangement. I could use or not use the purple and I'd still have a symmetrical spoke arrangement; likewise I could take or leave the yellow and it wouldn't really disrupt anything as far as a color scheme goes.
It's not important to have exact proportions of each color in your color scheme. In fact it's better to pick one as the main color (and it doesn't need to be the root color) and then use the others in small quantities. The smallness of the color doesn't affect the noticability of the color. If it's a symmetrically-shaped color scheme it will work even in tiny doses.