Discussion » Questions » Science and Technology » Why isn't the color purple in a rainbow?

Why isn't the color purple in a rainbow?

Posted - July 4, 2023

Responses


  • 23588
    I admit I don't know.

    And I've not paid much attention to rainbows since a young child - - though they're no doubt beautiful, they don't include my favorite color, brown. 
    :)


    Brown Rainbow | Pinkish Black This post was edited by WelbyQuentin at July 5, 2023 8:11 AM MDT
      July 4, 2023 6:02 PM MDT
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  • 8214
    I missed that one, never thought of brown.  It's hard to find brown clothing now as well. Brown used to be a go to color but not any longer.  
      July 4, 2023 7:11 PM MDT
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  • 53510

     

      I know, right? Grrrrrrrrrr.

      
      

      July 4, 2023 6:36 PM MDT
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  • 2131
    I told my mom my favorite color is purple and she's like ewww. Hers was yellow. Loose kid. Not the average house. This post was edited by CosmicWunderkind at July 5, 2023 8:12 AM MDT
      July 4, 2023 6:48 PM MDT
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  • 10052
    Violet is pretty much purple, isn't it? 

    Red
    Orange
    Yellow 
    Green
    Blue
    Indigo
    Violet
      July 4, 2023 6:46 PM MDT
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  • 8214
    It's close but not purple. 
      July 4, 2023 7:09 PM MDT
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  • 3758
    It's definitely in the purple family. :)
      July 5, 2023 4:17 AM MDT
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  • 3758
    According to the Encyclopedia Brittanica:

    Purple, magenta, and hot pink, as we know, don't occur in the rainbow from a prism because they can only be made as a combination of red and blue light. And those are on opposite sides of the rainbow, nowhere near overlapping. So there is no purple or hot pink in the rainbow from a prism.
      July 5, 2023 4:24 AM MDT
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  • 34331
    Because purple is a combination of red and blue light. 
      July 5, 2023 7:39 AM MDT
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  • 844
    No, purple is a combination of red and blue pigment.
    When blue and red lights mix, the result is magenta.
     
      July 6, 2023 6:20 AM MDT
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  • 34331
    You do realize that magenta is a shade of purple, right?
      July 6, 2023 5:02 PM MDT
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  • 44628
    Contrary to what a few have said here, purple is not a combination of different lights, but blue and red pigments.
      July 5, 2023 8:13 AM MDT
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  • 844
    Correct.
      July 5, 2023 10:46 PM MDT
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  • 844
    The colors of the rainbow are red, orange, yellow, green, blue, violet.
    Violet is as close to purple as you get in nature.

    The primary colors of light are red, green, and blue.
    The primary colors of pigment are red, blue, and yellow. 

    Combining colors is different when you're using colors of light or pigments.
    Mixing all the colors of light together gives you white.
    Mixing all the colors of pigment together gives you black. This post was edited by NYAD at July 6, 2023 6:42 AM MDT
      July 5, 2023 3:49 PM MDT
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  • 53510

      Wait, WHAT? I love that last line!

    “Mixing all the colors of pigment together gives you black.”




    ~

      July 5, 2023 6:10 PM MDT
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  • 844
    You bet your bottom!! 
      July 5, 2023 8:26 PM MDT
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  • 34331
    When you mix all the colors in pigments...you get brown not black. 
      July 6, 2023 6:44 AM MDT
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  • 844
    Did you look it up? I tried to copy the color wheels from the information pages but apparently I don't know how to do it. I learned this color information in science when I was a school kid. I looked it up again to be sure that the science had not changed/shifted since then. The color wheels and the explanations said black. Can you find me a link? Thanks.
      July 6, 2023 10:50 AM MDT
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  • 34331
    I don't have to look it up. I paint for a living.  The color will be brown. 
      July 6, 2023 11:35 AM MDT
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  • 844
    You can make any color by combining combinations of the primary colors by the percentage of each color of pigment. But, mixing the three primary colors in equal percentages would produce black. Any color in the world is actually made from combinations of the three primary colors by adjusting the amounts of the contributing pigments (and adding black or white). If you get brown, you've used a slightly higher or lower percentage of one or more of them.

    Some of the pigments that you purchase could have had pigments adjusted before you purchased them. Do you know if you're using a true blue, a cobalt blue, azure, etc.? That would make a difference. This would be true of paint used to paint walls, paint pictures, or anything else. I even found a site with more than a dozen shades of black.

    The thing is, we can both be right. I stole this from  azcentral.com: "It has been determined by people who determine such things that there are somewhere around 18 decillion varieties of colors available for your viewing enjoyment. That's an 18 followed by 33 zeros."

    The science is the science but to the rest of us it seems more theoretical. So, how many people have the real ability to distinguish what a spectrophotometer can? Not me.
     
    This post was edited by NYAD at July 6, 2023 1:25 PM MDT
      July 6, 2023 12:15 PM MDT
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  • 34331
    You did not say 3 primary colors used equally....you said mix all the colors to get black.  You get brown. 

    Yes there are millions of colors. Our eyes are wonderful tools that can detect these colors. We have cells (cones) that detect blue, red and green and use those to see all the colors based on which cones are activated and to what extent.  
      July 7, 2023 7:37 AM MDT
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  • 44628
    All colors are made up words. To one, it is violet...to another it is purple. This entire thread is moot. These are human definitions and can be interpreted any way we want. Nuf said.
      July 6, 2023 8:02 PM MDT
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  • 844
    Yes, that's true. Based on the number of variations (18 decillion varieties?), we could call them by their number on the scale that as read by technical equipment, but I don't think that would catch on.

    Boss Lady wanted to know why the rainbow has no actual purple, she just got way too much information.
      July 7, 2023 2:25 PM MDT
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  • 844
    My father was a true color blind person. The traffic lights were top, middle, and bottom to him. When he bought my mom something (socks, a kitchen bucket, etc.) it was always chartreuse, the only color he could distinguish from all the others. If you came to our house and saw something that was chartreuse, you would know that my father bought it.
      July 8, 2023 2:11 AM MDT
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