I always learned “ROYGBIV” as the colors of the rainbow. Red, orange, yellow, blue, indigo, violet.

What’s up with the last two? Isn’t indigo basically just dark blue? Why is it violet and not purple? Can’t it just be “ROYGBP”?

  • Dr Cog
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    1 year ago

    ???

    Purple is not a combination of wavelengths, it is a single one. And pink and brown are lighter/darker versions of other colors. Pink being light red, and brown being dark orange.

    • KaJashey@lemmy.world
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      1 year ago

      Depends on how you define purple. If violet is close enough to purple for you then that “purple” would be a single spectral color, a single or continuous set of wavelengths. If it’s just a little more like magenta it would be a non-spectral color. A combo of red and blue light.

      Plenty of non-spectral colors. Most things we see are non-spectral colors. Single pigments give off multiple wavelengths. Most things have combos of pigments on top of that. Emission spectra are multiple wavelengths.

    • beefcat@lemmy.world
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      1 year ago

      Purple is often defined as the color we perceive when something reflects blue and red light, whereas violet is a specific region of the light spectrum between blue and ultraviolet.