By distinguishing between wavelength and colour, and showing that the broad- band photopigment and its various forms responsible for the detection of different wavelengths do NOT detect colour, but rather incident photon energy (translated into wavelength for human convenience), colour can hence be thought of as an artificial construct of the brain imposed on reality. This has profound ramifications for our perception of reality.

If what we detect is not colour, then what does our world REALLY look like? And is there really any meaning to asking that question-- is there any absolute state of the world that different species, even different organisms within the same species, get only partial glimpses of through their specialised sensory apparatuses?

Much of our behaviour is based on being able to distinguish colour, being able to describe it and, in many cases, being able to reproduce it. Colour- blindness, then, presents an extremely interesting case because colour has such a different meaning for those who cannot detect what the majority of the population can. Sociologically, the dominant paradigm describes those people whose behaviour reflects the ability to differentiate between the red, green and blue primary colours. Thus, for example, traffic signals require differentiation in order to be able to function in accordance with laws set up by the general society.

Yep, profound ramifications for our perception of "reality". And for appreciating social conventions. Is worth keeping in mind that one can't, in general, presume all people are having the same experience. On the other hand, there is some substantial degree of ability of people to work with the same concepts at least. Which perhaps is the best we can do to try and get an idea of what the world REALLY looks like? Maybe better still if we understand better how it looks to different varieties of animals as well. Wisdom as the sum of lots of different "partial glimpses"? PG