What is COLOUR? Is the Spectrum peculiar to Humans only?

This is very simple but have you ever seen the Eric Stoltz film called Mask?
His character goes out with a blind girl and he tries to describe colour.He gives her cotten wool and says that they represent clouds and white.
He also gives her a hot potato and he says that is red and when it ccols down it will be pink.

Color is a result of the frequency of light. Light that appears red may be red or may be a combination of many frequencies, but with a defficiency of a complimentary frequency (probably green). Those animals that can see color at all, probably react to frequencies similarly to humans, because the visible range of EM radiation frequencies is really based on the sunlight frequencies that penetrate the atmosphere well.

and some can see colours we can't - like insects, who can see ultra violet rays and flowers have incredible patterns on them that we don't see

link to pictures

What about sea creatures - any examples of what colours they can see?

There is a wild cat(maybe all)that only see in black and white hence zebras having great camoufkage in tall grasses.

Are you serious? Check out what its called and post your results here.

In addition to many insects seeing ultraviolet many beetles see infrared.

Why do the beetles not ALL see the same colour spectrum?

Wish I had a site on this but I don't . I remember reading it in a book not on the web. I do know that there's a great diversity in insects eyes and they vary greatly with the greater majority seeing in the ultraviolet range. I'll see if I can find more info.

Thanks Bob - I'll look forward to that.

Well, this is turning into a marathon. Different insects have different eyes and differ in the way they see. All beetles do not have the same vision. I found the book where I originally read this (2201 Fascinating Facts by David Louis Greenwich House distibuted by Crown Publishers Inc. New York 1983)

article: Insects can perceive a range of light far greater than that discerible by man. Most insects, for instance, can see ultravioletlight,and many varieties of beetles can see infrared. Insects are unable to focus their eyes, however, and can discern objects clearly only from several inches away. Most insects eyes are made of tiny six-sided lenses, and sometimes (in the dragonfly, for instance) as many as 30,000 of these lenses cover the retina. This means that insects do not perceive a single image, as humans do, but see a staggering number of separate images that, when combined, would appear to us as a colossal mosaic. Insects, furthermoe, have no eyelids. Their eyes are always open.

I've looked at a lot of sites in the interim with very little success. One site confirmed and more stated that occasionally people, in particular, women are born as tetrachromats. That is they see 5 colors rather everyone else who are trichromats.

Here is the site:

1.
Superhuman Tetrachromats (PDF) Open this result in new window
... other types of colour vision abound. Insects exhibit some of the more impressive ... further into infrared wavelengths, enabling them to see beyond the natural limit of human ...

www.ryansutherland.com/media/tetrachromats.pdf

Thanks Bob. That was interesting.

Happy to do it, my friend. After all I learned too. And that is a good thing.