I saw this rainbow today at about 7.15 PM in North Yorkshire. It was almost directly above me and seemed to be on the edge of a cloud. It was "the wrong way up" as you can see in the thumbnail. The white line to the left is a plane vapour trail. Weird It was visible for a good 15 minutes. The only similar thing I have seen was a rainbow around the sun, directly above, at midday, in Brazil. Never seen anything like it in the UK and it certainly was not around the sun.