Early Morning Ponderings : The Nature of Colour

[gamblore99]

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Colour is your brain's way of telling you that the light you're seeing is of a particular wavelength (or combination of wavelengths).

To see an object in a certain colour means that it reflects (or emits) that wavelength (or wavelengths) of light. Which wavelengths it reflects depends on how the particular structure of its atoms and electrons interact with photons of light.

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I would further add that how we percieve a colour of an object depends on its background. Also negative afterimages, can make something appear to be a different colour by bleaching the colour receptors.

Here is a link to a quick afterimage experiment

afterimage

So in conclusion, objects emit certain wavelengths, how we interpret them determines what colour we see them. This interpretation can be changed depending on a variety of things. Colour is in the mind.

It depends slightly on the background. No matter what color you superimpose pink on, you won't see it as green, but the shading may change slightly. So the color is still independent of the brain, bar some small corrections made by our visual processing software and hardware.

Also note that bleaching of pigments etc doesn't mean that color resides in the mind. That's like putting a magnet on my download cable, corrupting the data stream, and then claiming that the data doesn't exist independent of my computer (or resided there).

[gamblore99]

Phil, I really don't like your computer analogy. Negative afterimages do not involve any outside effects on the eye. They are caused by just looking at one colour for a short time. Second the changes caused by the background can be very dramatic, more than a change in shade. Our mind percieves colour based on a colour contrast mechanism. I have to study now, and I don't know the details off the top of my head, but I will bust out my textbook and get some more in depth explanations for this thread later tonight.