How is colorblindness recognisably different from equality?

Answer 1

My answer does not pretend to be more than partial, I think there is a problem with identifying certain conceivable types of colourblindness, i.e. if a person has always seen every shade of what a 'normal' person believes to be red as blue and vice versa then they will call their blue red, their red blue, and there will be no way of recognising that when they say "it is blue" they are seeing red. However this is not exhaustive, if a person cannot appreciate the difference between green and yellow it will be obvious that their way of seeing colours is not equal to the standard, similarly if the 'colourblind' person sees certain shades of green as part of their brown colour family others will notice that their colourblind perception of what they experience is unequal to the colour consensus. As a footnote I must say that I believe the first question - of polar discrepancy - is much more interesting, how can can we know that another consciousness is using the words we seem to agree on to describe the same things as we are?