[tempguy9999]

Bruises can be blue, also black. I don't see a problem.

Also I came across a study that suggested primary colours were distinct and absolute categories (not relative). They put babies in front of various colours and measured how long their attention was on the colour. Primary colours got more attention, from this they deduced what we called primaries were perceived as having a common reality. I can't find the study so this paragraph is an FYI, sorry.