Over natural (very dark brown) hair with a few slightly lighter highlights, this actually showed up very well. It was very easy to apply and I was surprised how green it was; mine appeared less bluey than the picture there. I got lots of comments, including one from a stilt-walker who pointed me out to his friends. It also lasted extremely well, vibrant for over a month until I dyed over it for university (they aren't too keen on unusual hair colours in their enrolment photos...)