Ann wrote: ↑Tue Apr 16, 2024 5:01 am All I can say is that purple light triggers a response from both the blue-sensitive and the red-sensitive rods in our retinas. Consider this color, ███. The (rgb) values of this particular color is, r = 123, g = 0, and b = 222. So purple, at least as far as our eyes are concerned, is indeed a mixture of red and blue.
I can see that the mixture of red and blue light in the sky under certain circumstances will make parts of even in the cloudless dawn or dusk sky look purple (because the atmosphere itself will reflect light and provide some mixing of the colors). I know I have seen clouds reflecting the dawn or dusk light look purple (but mixed with other colors as well).
Ann
Ann, that’s very interesting to see the purple color with rgb values of r = 123, g = 0, and b = 222. The b = 222 is a high value -- approaching the maximum 255.
I am wondering how to describe the blue in the upper atmosphere behind the purple clouds in the first photo. It looks as if it is during blue hour. Do you think blue rgb values of blue hour would be lower than 222?