my reasoning: the actual colors we can see -> the wavelengths that we can extrapolate to -> basically extrapolated wavelengths plus an 'unpure-ness' factor -> not even real wavelengths (ok well king blue and maybe lavender if I'm being generous could be)
They are for subtractive color. Additive is RGB. But it's not that the colors are "different" per se, just that properties of light versus pigment are different when blending. Your eyes still interpret both the same.