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Am I interpreting this correctly, that the extraspectral hues, i.e. magenta, can only exist in the mixing of two materials? If so this seems to explain why you

Am I interpreting this correctly, that the extraspectral hues, i.e. magenta, can only exist in the mixing of two materials? If so this seems to explain why you have never seen a magenta flame (but you have seen red and yellow and green and blue). It would also seem to suggest that a magenta pigment must be some combination of at least two different molecules. Is that right?

zarzavat 5y ago
For the first, physical hues form a straight line continuum, from red to violet. The human eye samples these hues at three overlapping points (RGB) and then the visual pathway does some math to reinterpret RGB as a closed circle of hues we see in our visual field. For the second point, while monospectral light cannot produce magenta, you don't need multiple molecules to reflect multispectral light.
- artiszt 5y ago
  >the visual pathway does some math to reinterpret RGB as a closed circle of hues we see in our visual field< sort of, computation of 'contrast' so to speak, or, in broad terms, differences in wavelengths most likely done, foremost and in essence, in area V4, cortically. if damaged, cerebral achromatopsia [colour blindness results]. patients won't even see/perceive induced 'coloured' visual phenomena, such as phosphenes [Farady made a few quid by electro-shocking ppl, for instance in Jardin des Tuileries, Paris : electro-magnetc impulses applied transcranially to the occipital part of the brain can elicit, in some subjects, brief bright colourfull light sensations]
raphlinus 5y ago
The extraspectral hues require mixing light of at least two different wavelengths (red and blue in different proportions), while the other hues can all be made from a single wavelength of light. I understand that lithium chloride can burn with a magenta flame, but that just means that its combustion reaction produces light with that particular distribution of wavelengths in its spectrum - similar to a white flame which would have red, green, and blue. Pigments work differently than light emitting sources, as they absorb light that is not present in the reflected color. So a magenta pigment is not all that special, it just means it absorbs green. Quinacridone and crystal violet (hexamethyl pararosaniline chloride) are two such examples, each capable of a brilliant magenta or purple color from a single molecule.

zarzavat 5y ago

For the first, physical hues form a straight line continuum, from red to violet. The human eye samples these hues at three overlapping points (RGB) and then the visual pathway does some math to reinterpret RGB as a closed circle of hues we see in our visual field. For the second point, while monospectral light cannot produce magenta, you don't need multiple molecules to reflect multispectral light.

artiszt 5y ago
>the visual pathway does some math to reinterpret RGB as a closed circle of hues we see in our visual field< sort of, computation of 'contrast' so to speak, or, in broad terms, differences in wavelengths most likely done, foremost and in essence, in area V4, cortically. if damaged, cerebral achromatopsia [colour blindness results]. patients won't even see/perceive induced 'coloured' visual phenomena, such as phosphenes [Farady made a few quid by electro-shocking ppl, for instance in Jardin des Tuileries, Paris : electro-magnetc impulses applied transcranially to the occipital part of the brain can elicit, in some subjects, brief bright colourfull light sensations]

raphlinus 5y ago

The extraspectral hues require mixing light of at least two different wavelengths (red and blue in different proportions), while the other hues can all be made from a single wavelength of light. I understand that lithium chloride can burn with a magenta flame, but that just means that its combustion reaction produces light with that particular distribution of wavelengths in its spectrum - similar to a white flame which would have red, green, and blue. Pigments work differently than light emitting sources, as they absorb light that is not present in the reflected color. So a magenta pigment is not all that special, it just means it absorbs green. Quinacridone and crystal violet (hexamethyl pararosaniline chloride) are two such examples, each capable of a brilliant magenta or purple color from a single molecule.