> Basically, colors have three "axes": hue (is the color red? blue? yellow? green? purple? etc), saturation (how _much_ of the hue is there? low (but not 0) means pastel; high means neon), and brightness (low is black, high is bright).
Not quite. Or, to be more accurate, the naive HSV is a poor approximation of the perception process.
The visual process is dominated by a luminance scale--the perceived amount of total light. Not all wavelengths contribute equally to it (which is where HSV goes wrong). L is devoid of color information; grayscale images would only have an L channel. Then there is hue, which is essentially a mix of red-versus-green and yellow-versus-blue but is generally described as an angle. There is also a colorfulness property, which is roughly how much the spectrum departs from a flat spectrum.
Except the visual process is more complicated: these values are both considered in absolute and relative terms. A grey that's surrounded by dark greys looks lighter than if it were surrounded by light greys. So you can't look at a color in isolation, you have to consider its context; CIECAM maps colors not to 3 dimensions but to 6 dimensions. This makes accurately mapping a numeric range to colors very difficult.
Finally, there's an added complication when trying to represent colors of physical objects rather than computer screens: there's a difference between specular and diffuse reflections.
Not quite. Or, to be more accurate, the naive HSV is a poor approximation of the perception process.
The visual process is dominated by a luminance scale--the perceived amount of total light. Not all wavelengths contribute equally to it (which is where HSV goes wrong). L is devoid of color information; grayscale images would only have an L channel. Then there is hue, which is essentially a mix of red-versus-green and yellow-versus-blue but is generally described as an angle. There is also a colorfulness property, which is roughly how much the spectrum departs from a flat spectrum.
Except the visual process is more complicated: these values are both considered in absolute and relative terms. A grey that's surrounded by dark greys looks lighter than if it were surrounded by light greys. So you can't look at a color in isolation, you have to consider its context; CIECAM maps colors not to 3 dimensions but to 6 dimensions. This makes accurately mapping a numeric range to colors very difficult.
Finally, there's an added complication when trying to represent colors of physical objects rather than computer screens: there's a difference between specular and diffuse reflections.