<p>It a <a href="https://en.wikipedia.org/wiki/Rainbow#Supernumerary_rainbows">supernumerary bow</a>, which results when the droplets that create the rainbow are very small and of nearly uniform size. The droplets need to be small enough so as to make diffraction a significant effect.</p>

CC BY-SA 3.0
2016-07-13T00:18:07.690Z
Thank you. Good info on that phenomenon here: http://www.atoptics.co.uk/rainbows/supers.htm
Cameron Brick
CC BY-SA 3.0
2016-07-12T17:38:23.967Z
2016-07-13T12:58:36.380Z
2016-07-13T12:58:36.380Z
David Hammen
<p>I saw a rainbow outside Silverton, CO last week that for a few minutes seemed to show part of the color cycle (red to purple) several times within the same band. This picture is how it looked to my eye. I assume this is some refraction phenomenon of multiple rainbows, or ... ? It was also a double, but that part isn't shown. </p>

<p><a href="https://i.sstatic.net/T1VcY.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/T1VcY.jpg" alt="showed this banding for a few minutes"></a></p>

<p>I took another picture a few minutes later of it looking normal (the rainbow brightened, the droplets were bigger, and there was a strong double):</p>

<p><a href="https://i.sstatic.net/gDO69.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/gDO69.jpg" alt="enter image description here"></a></p>

<p>What is causing this strange banding? </p>

<atmosphere><atmospheric-optics>
Explanation for single rainbow that contained colors several times
Cameron Brick
# Explanation for single rainbow that contained colors several times

(Asked by: username_0 on 2016-07-12)

I saw a rainbow outside Silverton, CO last week that for a few minutes seemed to show part of the color cycle (red to purple) several times within the same band. This picture is how it looked to my eye. I assume this is some refraction phenomenon of multiple rainbows, or ... ? It was also a double, but that part isn't shown.

[![showed this banding for a few minutes](https://i.sstatic.net/T1VcY.jpg)](https://i.sstatic.net/T1VcY.jpg)

I took another picture a few minutes later of it looking normal (the rainbow brightened, the droplets were bigger, and there was a strong double):

[![enter image description here](https://i.sstatic.net/gDO69.jpg)](https://i.sstatic.net/gDO69.jpg)

What is causing this strange banding?

**Tags:** atmosphere, atmospheric-optics


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## 1 answers

### Answer by username_1 on 2016-07-12. Score: 7 | Accepted answer

It a [supernumerary bow](https://en.wikipedia.org/wiki/Rainbow#Supernumerary_rainbows), which results when the droplets that create the rainbow are very small and of nearly uniform size. The droplets need to be small enough so as to make diffraction a significant effect.

> **Comments:**
> **username_0**: Thank you. Good info on that phenomenon here: http://www.atoptics.co.uk/rainbows/supers.htm  

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