I came across an interesting article on “Colour as content, not surface”. Written by Timo Rieke.
Below the short extract:

(…) “Colours appear rough or smooth, soft or hard, sharp or rounded, heavy or light, or flat or spatial. To understand the meanings of colors, it can be useful to understand sight as a sort of touch, but also as a type of hearing and smelling at a distance”. (…)

The entire article here.