A rainbow coloured cloud?

Wasn't sure what I was looking at as I stood doing the washing up today, so I went outside and tried to get a picture of it. Not enough zoom to photograph it well I'm afraid. 
Lately I've heard of 'nacreous' clouds being seen in Scotland sometimes, but I really don't know if this is one, and there weren't any others to be seen, as far as I could tell. Perhaps someone else can put me right about what it is! 
The extras are to show it a bit closer. I put a filter on the second one to try and make the colours stand out more.