Colour Perception

Should I spend a fortune on very accurate computer monitors? Should I buy very expensive paints?

We can see millions of colours. Graphic artists will be familiar with this but how is this number arrived at. With a monitor it’s easy, colours are generated with a very specific method, RGB (red green and blue pixels), that can produce millions of possible colours. Each pixel can be set to one of 256 possible values. So 256 x 256 x 256 is 16,777,216 possible values. So why is it that I sometimes have difficulty matching a colour to something I am seeing? Depending on the colour method being used, and how it’s defined, there may be millions or even billions of possible colours that can be generated. Our retinas are probably not capable of differentiating billions of colours but it might be necessary to produce more than millions of colours in order to replicate certain areas that our retinas can perceive very accurately. Greens for example.

Our retinas don’t differentiate colours in a linear fashion; in some areas of the spectrum our retinas may be very sensitive and in others not so much. So in some areas of the spectrum we can differentiate colours that would divide the spectrum into multiple millions of colours and in other areas thousands of colours might be close enough. For example we are very good at seeing greens. This is why fluorescent lights are designed to fluoresce more in the green parts of the spectrum (this might be a lucky coincidence). This allows a lower wattage bulb to appear brighter. Since we evolved in a forest it’s understandable that we can differentiate greens better. From an evolutionary perspective we might have evolved to better see the Lion in the grass.

Although interesting this doesn’t really help the artist (me). I try to fiddle with colour and use various pigments that I think are closest to the colour I want to achieve. I know that a human’s colour vision isn’t particularly accurate and I have a significant amount of trouble trying to match some colours accurately or acceptably. This might seem very disheartening to many who are trying to reproduce specific colours but I think it has a great deal to do with what I call the reality illusion so I embrace it. So long as the painting looks good I try not to be too concerned about why. I don’t recommend spending a fortune on a colour monitor. If you really like the colour of a paint then buy it and try it out.

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