i think that they look good if they are done in a way that they are completely hidden. I do not have the patience to do it so i don;t put them on my bike, but it is not out of the question one of these days
I went to look at a bike today that had some subtle color changeable led lights on a VFR 800. It was fun for grins and giggles. I like that he had a remote on the keychain to be able to change the colors/effects. Seems like a fun thing to me if done right, but I do understand the stigmas associated.
There might be some saftey gain due to better visibility at night I suppose.
Just be careful on the color due to legal issues in some states.