Be careful! I was in the hairdressers yesterday when a very upset young lady came in. She'd had her hair tinted a light brown (at the hairdressers), then had put on a blonde colour herself, and yes, it had gone orange. The hairdresser did explain what had happened, and I think it was that the bleach sets the colour. The hairdresser said that they would have used a bleach wash first. Anyway, it was going to cost her a fair bit to get it sorted. As I left they had snipped out a bit of her hair and had put it into two different colours to see if either of them would take, but they said if it went wrong she could have bald patches.