everything is relative. just because several may believe something to be true does not ensure its accuracy. sure something may be widely accepted, but is it true?
It will remain the consensual truth until proven otherwise. Prove to me for example the sky is green and convince the rest of the world the same, it now becomes the (new) truth.
because color blind does not mean that, everyone thinks that color blind means seeing colors different, when in reality it means , not being able to identify what colors coordinate with others.
The sky has no colour. It is an optical illusion. Look at the sky at night, and ask yourself "What colour is it?"