Think of mixing colors. If you mix 50/50 red & blue, obviously that's purple. When it's 80/20 red & blue, that looks more red than blue but looks purple but n

Think of mixing colors. If you mix 50/50 red & blue, obviously that's purple. When it's 80/20 red & blue, that looks more red than blue but looks purple but not the same as above. When it's 20/80 red & blue, that looks more blue than red but looks purple but not the same as above. It's a classification using a gradient, not an integer so yes, the boundaries are hard to tell but are still there.