I think this style looks good when it appears to be oh-so natural, when you have mousy-brown roots and then slightly blonder ends. I see so many girls with really dark roots and then bright blonde tips and it looks hideous.
I fell in love with Alexa's uplighted hair and I really want to get it done, but I'm worried my hairdresser might get it wrong. I might hunt for a better colourist before I go for it, but I definitely will be getting it done after I finish my exams and start my summer holidays in a fortnight!
I'm going to take some pictures of Alexa and that gorgeous picture from Garance Doré... the girl in that picture has gorgeous hair too; very similar to Alexa's but with a bit more volume. Thanks for posting that picture!