Problems? Is your data what you think it is? PerlMonks

### Re: How many colors does a rainbow have? (8)

by tye (Sage)
 on Jan 25, 2009 at 06:17 UTC ( #738757=note: print w/replies, xml ) Need Help??

in reply to How many colors does a rainbow have?

I voted 6 because I never saw the point of separating "Indigo" and "Violet" (and ROYGBP maps nicely to three primary colors plus three secondary colors).

Then I searched around for some decent pictures of real rainbows. At first this confirmed my previous impressions; they all looked like they went from "Blue" to "Purple" then ended.

They also ran quite suddenly from "Red" to "Yellow" making "Orange" rather hard to pick out while "Green" through "Blue" were clearly not sufficiently represented in "ROYGBIV".

After reviewing several pictures of rainbows in the sky and from prisms, the best list of colors I could come up with was: Red, Orange, Yellow, Green, Teal, Cyan, Blue, Purple. The only picture that gave me an impression of separating "Purple" into "Indigo" plus "Violet" was http://people.rit.edu/andpph/photofile-c/prism-DSCN4982.jpg. Perhaps it is just that "Violet" tends to be quite faint.

Update: Then I went to look for cannonical examples of "Indigo" and "Violet" and found confirmation of my first point:

Although traditionally considered one of seven divisions of the optical spectrum, modern color scientists do not usually recognize indigo as a separate division and generally classify wavelengths shorter than about 450nm as violet.

This was immediately followed by something that was educational to me:

Indigo and violet are different from purple, which cannot be seen on the electromagnetic spectrum but can be achieved by mixing mostly blue and part red light.

Which rather reminded me of the term "monkey". Practicing biologists know that humans and (other) apes are not monkeys while non-biologists know that apes are a type of monkey (as are humans). I know that the color at the end of the rainbow is a shade of purple, despite what practicing spectrumists might believe. :)

Update: Actually, "Green" is still insufficiently represented. ... Yellow Lime Green Teal Cyan Blue ... seems more accurate. (Leprechauns++)

"Rainbows Only Yield Gold To Cannabis-Burning Potheads" - tye

• Comment on Re: How many colors does a rainbow have? (8)

Replies are listed 'Best First'.
Wikipedia gives interesting results of the spectrum
by freakingwildchild (Scribe) on Jan 30, 2009 at 11:23 UTC
http://en.wikipedia.org/wiki/Visible_spectrum would give 6 colors,
http://en.wikipedia.org/wiki/Rainbow would give 7 colors ...

In the rgb theory the prisma could also have 6768-1 colors, refered to http://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Spectre.svg/744px-Spectre.svg.png

I've just been counting the colors in the visible spectre image below, 6768 colors including the black waveline... but I think I'm just pulling the line a bit too much now ;)

Personally I think infinity-1, with 7 distinct visible differences.

Re^2: How many colors does a rainbow have? (8)
by prysmatik (Sexton) on May 10, 2017 at 17:50 UTC

I saw a great video once about how Blue & Red form purple. Basically that it's an imaginary color or some such made up by the brain.

"The Mystery of Magenta"

Not trying to advertise content or what not, so I guess I'll leave it to you to search it out.

But I found it interesting.

Basically something about how we're connecting 2 ends of the color spectrum by going the OTHER way.

Create A New User
Node Status?
node history
Node Type: note [id://738757]
help
Chatterbox?
 [holli]: I got into a fight yesterday and won. [holli]: No, that's not true. I started it. [holli]: I was company to my mother, bringing her to the therapy she has to take. There was another so called therapist outside smoking. We engaged in a talk with her and he turned out to be one of these lunatics telling people when they are sick it's their own [holli]: fault for not thinking positively enough. [LanX]: did he seriously hurt his fist at your nose in the end? LanX .oO(positively thought) [holli]: :) No. I might be small, but you don't want to be around me when I flip. [LanX]: I can imagine ...

How do I use this? | Other CB clients
Other Users?
Others making s'mores by the fire in the courtyard of the Monastery: (6)
As of 2017-12-13 17:57 GMT
Sections?
Information?
Find Nodes?
Leftovers?
Voting Booth?
What programming language do you hate the most?

Results (373 votes). Check out past polls.

Notices?