• bstix@feddit.dk
        link
        fedilink
        English
        arrow-up
        9
        ·
        10 months ago

        In short: Purple doesn’t have it’s own wavelength. Neither does white, black and the entire gray-scale or any mixing of any colour with the gray-scale and probably more. They’re called non spectral colours.

        It might be easier to understand when considering other types of waves. At least it is for me. A simple sound can also be described as a wave with a frequency, but if we play two sounds at the same time, we can’t say that the sum of the waves has any specific frequency. The frequencies don’t add up or multiply or mix as average. The combined sound can only be described as the addition of two frequencies.

        In musical terms, purple is not a note, but instead a chord or interval. Red and blue can be individual notes, or they can be mixed as intervals. White is noise and black is silence.

      • Saik0@lemmy.saik0.com
        link
        fedilink
        English
        arrow-up
        17
        arrow-down
        9
        ·
        edit-2
        10 months ago

        Just look at the spectrum chart here. https://www.thoughtco.com/the-visible-light-spectrum-2699036

        Red + green = yellow…

        Green + blue = cyan…

        Red + Yellow = Orange…

        Red + blue(indigo) = a color not on the chart? but in between the two colors is clearly green!

        We perceive purple as an activation of Red and Blue cones in our eyes… The color itself actually doesn’t exist as a discrete wavelength and is a collective hallucination of sorts.

        Edit: Also… Brown isn’t a color. https://www.youtube.com/watch?v=wh4aWZRtTwU (whoops, wrong link originally, fixed now.)

        • Supervivens@lemmy.world
          link
          fedilink
          arrow-up
          16
          arrow-down
          2
          ·
          10 months ago

          Fine do you want to call it a violet onion then? They are basically the exact same damn thing and violet is a wavelength

          • Saik0@lemmy.saik0.com
            link
            fedilink
            English
            arrow-up
            4
            arrow-down
            5
            ·
            10 months ago

            https://jakubmarian.com/difference-between-violet-and-purple/

            Violet and Purple are indeed not the same thing. Purple exists in that we perceive it… that’s not what I’m arguing against. It’s just that it’s not a “real” color. It’s only because of this “mass hallucination” of sorts that we’re okay just accepting that it must be a color when it isn’t representable as a single spectrum color like every other color. It is purple… but purple isn’t a real color, it’s effectively just shorthand for saying that this color is both blue and red. It’s just you being human.

            Brown has the same problem in that it’s just dark orange (from the light spectrum perspective). It turns out that brightness context matters to us, so we choose brown to represent a large swath of that.

            • brbposting@sh.itjust.works
              link
              fedilink
              arrow-up
              1
              arrow-down
              1
              ·
              10 months ago

              I have a shorthand for “only real in the context that it’s real for humans”… hint, it has four letters and starts with “real”.

              :) interesting info!

        • And009@lemmynsfw.com
          link
          fedilink
          English
          arrow-up
          7
          ·
          edit-2
          10 months ago

          You’re right about our perception but the color spectrum is based on wavelengths and doesn’t represent color mixing. It only does that when you make a circle out of it and then you see purple between blue and red and that’s your standard RGB color wheel.

          Colored lights do mix. It’s called an additive color since you are adding different lights to create a new color. So red and blue light does Infact create purple light and to get green you have to mix red and yellow light. Mixing RGB or CMY creates white this way.

          The other is subtractive color mixing, like when we paint, to get green we mix blue and yellow instead. Mixing CMY, RYB or RGB would give you black.

        • Undaunted@feddit.de
          link
          fedilink
          arrow-up
          0
          ·
          10 months ago

          Just because violet light triggers both red and blue receptors in our eyes, that doesn’t mean there is only discrete red and blue light hitting them. It’s just that light with 380nm to 450nm wavelength triggers both typed of receptors. So there is violet light.

    • Shayeta@feddit.de
      link
      fedilink
      English
      arrow-up
      0
      arrow-down
      1
      ·
      10 months ago

      I think it’s better to make the distinction between color and light wavelenght instead of just saying purple isn’t real.