I have friends who love doing it. I have one friend who loves everything about decorating including hanging lights outside and the Xmas tree and so forth. I know some people do like doing it sometimes. I - on the other hand - have walked right past entire lit up displays and just really not noticed they were there -So then there's people like me.
But it is always good, I think, to do things that make one happy and if that includes decorating a tree with blue lights - then I am all for it.