3 ms·
Rob is right that in RGB cube 3 points always form a triangle. However, that color space does not include "true" purple (or violet), which is defined as light w
by Miiko 5y ago
Rob is right that in RGB cube 3 points always form a triangle. However, that color space does not include "true" purple (or violet), which is defined as light with shorter-than-blue wavelength, it only includes magenta = red + blue, and apparently Rob does not understand the difference.
The question is not why magenta is close to red - this is obvious, - but why magenta and violet are perceived similar by human eye, and that cannot be possibly explained by "cyclic nature of triangle" in RGB cube (simply because there is no violet in that colorspace at all).
- dahart 5y agoYeah, exactly. Spectral colors don’t exist in this RGB cube, only linear combinations of 3 specific primaries do. I agree with you - the question of purple has not been adequately answered, and I’m also becoming convinced that the subtlety and deepness of the question is not being understood or appreciated in the answer offered above. Just because people plot colors on a wheel doesn’t explain why pure violet is perceived as containing red. I’d say it’s probably the other way around - that one likely reason that artists in the past put red-purple-blue on the color wheel is because purple was already ambiguous - there’s a strange perceived similarity to the colors on opposite ends of the rainbow. A perceived red response to short wavelength blue colors, aka the left hump, is better at explaining the color wheel than the color wheel is at explaining purple.