# Is the "indigo" stripe of the rainbow more blue or violet?

**URL:** <https://boards.straightdope.com/t/is-the-indigo-stripe-of-the-rainbow-more-blue-or-violet/925700>\
**Category:** Factual Questions\
**Created:** [November 16, 2020, 11:54am UTC](https://boards.straightdope.com/t/is-the-indigo-stripe-of-the-rainbow-more-blue-or-violet/925700 "2020-11-16T11:54:55Z")\
**Posts on this page:** 1\
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**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\
**Post date:** [November 16, 2020, 12:12pm UTC](https://boards.straightdope.com/t/is-the-indigo-stripe-of-the-rainbow-more-blue-or-violet/925700/2 "2020-11-16T12:12:57Z")

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> [@themapleleaf](#):
>
> In actual fact, is there any substantial red content in the “indigo” stripe, which would make it a shade of violet/purple (or at least “blue-violet”, I.E. the tertiary color), or is it really a more or less pure blue? Has this even been determined scientifically, or is it purely a matter of perception? Is it more of a gradient? I.E., is the “indigo” stripe actually part blue and part violet?

The red pigment in the eye has a small amount of reaction to deep blue/violet wavelengths. So they look purplish, even though they don’t have any actual red color.

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