@davidbaron When using a single wavelength of light, there are colors you can't produce.
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@davidbaron Some colors are impossible with any amount of light, but you can trick your eyes into seeing them (super green, for example).
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@davidbaron The fact that spectral yellow and non-spectral yellow look the same isn't an accident, but purple vs red+blue *is*.
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@tabatkins No, I don't buy that distinction. They're both the result of a 3-D space.
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@davidbaron Or you're arguing at the wrong level of discussion, more abstract than the physical basis that I'm talking about.
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@davidbaron Abstractly, purple is just a blue and red response, with low green response. But that's impossible to do with single light color
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@tabatkins Sure, spectrum is 1-D and our vision is a 3-D subspace of an ∞-D space of functions from that 1-D space to reals.
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@davidbaron Yes, and again, that explains why red+green looks similar to spectral yellow. But not red+blue looking like purple.
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@tabatkins Red + green looking like spectral yellow is just a function of the actual response curves; little to do with linear spectrum.
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@davidbaron It has everything to do with linear spectrum! Linear spectrum + overlapping curves means "averaging" close colors works!
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@tabatkins but only because the curves happen to be mostly single-peaked and similarly-sized
Jul 28, 2014 · 8:20 PM UTC
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