Ok so I got my hair highlighted blonde (t bar) 2/3 weeks ago and underneath my hair is really dark. My roots are coming in already and I am wanting to dye it maybe a ginger/auburn colour or a light brown. I'd be doing this at home on my own. The problem is that I've heard this can turn it green?! What should I do to avoid this as I can't afford to go back to the hairdressers to get it done properly this month.
Thanks!