I've not had a problem perceiving colour on planets...even back in the days of my little 6" scope, Jupiter is white stripes with bands of beige, brown, salmon, and blobs of grey/blue and brick red. Saturn has always been pale yellow, with darker more beigey bands on better nights, Mars orangey-red, Venus is opaque white with hues around the edges.
Not sure about the learning thing. They've just always been coloured for me
