I was outside walking my dog on the east side of my house. Looking east into the clouds ( been raining all day ) I noticed it was sunset orange over there. I thought that was weird and just kinda starred that way for a piece.
then noticed a sunset orange/red beam coming up from the horizon. I couldnt figure it out. Looked lime a red spotlight maybe but why? Then as my eyes focused more and the angle of the sun dropped in the west a toich more I saw it grow in an arch and I knew what I was looking at. A red rainbow!
If I hadnt read about them two weeks ago I would never have figured it out. They seem kinda rare. Way it works is the same reason sunsets are red orange. During a normal rainbow all the colors of the spectrum are available to be refracted like a prism in the moist air. But as the sun drops, the higher frequency light gets filtered out by the atmosphere ( the violets and blues ) leaving only the low frequency waves to be refracted. So as the sun drops the light becomes more orange and red, with the other colors filtered out the available spectrum is all that is left to be shown in the rainbow. Sunset/sunrise rainbows are red orange. I tried for a pic but it didnt last long enough.