The top way is a much more logical way to organize the colors than the bottom. What we call blue is really two different colors lumped together for some weird idiosyncratic cultural reason that has nothing to do with the underlying reality of things, and orange is really nothing more than the thin slice of wavelengths bordering yellow and red, but can't be thought of as the same type of thing as the other colors due to it only occupying a narrow band of wavelengths. The six main colors are red, yellow, green, cyan, blue, and violet.