In my opinion, a blind person can surely distinguished two colors " Black and a white"..:-) and may be later through the help of a family members or friends and some expertise a blind person may or will have a perspectives about others colors. Anyways, we human came from nothing but born for something. Isn't? Hence then all things can be learned or practice.
I think his question is not about Color blindness. It's about how do blind people perceive color at all.
They see all the colours in the rain bow exspet all the colours in the rain bow.
Most blind people are not totally colour-blind and easily distinguish between certain colours or variations between two colours. For example, if a person is a blue-green colour-blind individual, it means that he or she has trouble distinguishing between the colours blue, violet, pink and grey. A lot of individuals who are colour-blind, in fact, can still see shades of colour. It is popularly believed the individuals who are colour-blind can only see the two basic colours, namely black and white, but that is an incorrect statement.
For instance, it is not clear whether a colour-blind person cannot see a rainbow or not. A person who is blind (even though the phrase visually challenged in a more politically correct term) cannot see a rainbow. On the other hand, a colour-blind person is a person who is unable to distinguish certain colours, such as red and green. Red and green appear to be the same colour to an individual who in colour-blind.
For instance, it is not clear whether a colour-blind person cannot see a rainbow or not. A person who is blind (even though the phrase visually challenged in a more politically correct term) cannot see a rainbow. On the other hand, a colour-blind person is a person who is unable to distinguish certain colours, such as red and green. Red and green appear to be the same colour to an individual who in colour-blind.