Don't take their advice.
Wanted to try coloring my hair at home and asked a sales person for some help. She seemed to know what she was talking about so I took her advise. My hair turned orange, and this is no lie. I ended up paying $300 to fix the color, and the damage will be with me for another year, until it grows out. Don't listen to these people. The best advise they could have given me was to leave it in the hand of a professional.