I logged into to test this evening and lo and behold I had a new hairstyle and color!
My hair usually looks like this:
i.imgur.com/vU0nR.png
But when I logged in it had been changed to this:
i.imgur.com/DqQBW.png
I changed it back and so far so good but maybe the hairstyle gnomes will visit my avatar again while I'm away :)