I have mid brown hair, hairdresser has put blonde highlights in but they are a very cool ash blonde and the overall effect is really deadening and unflattering. I'm going on holiday next week so can't go back to get them fixed beforehand, what can I do at home to add a warmer tone to the highlights without obliterating them completely? I was wondering about Scott Cornwall hair toner in caramel, has anyone used this or does anyone have any other suggestions? Thanks!