At sunset, when refraction is most pronounced, there can actually be three images of the sun a blue one on top, a green one in the middle, and a red one at the bottom. Each overlaps the others. You never see the blue because the blue light is scattered so severely that it doesn’t even reach the eye, once in a while though, and typically for less than a full second, a bit of the green light gets through. The guys on the Omani tri, Musandam, have been hoping for that, but no luck yet. Anyone got Green Flash pix? Send em in.
Pic from on board Musandam, as the guys get accustomed to colder climes, is from Oman Sail. There’s more here.