To William -Re follow-up to red hair coloradvice

WilliamThanks for all your help with my haircolor questions regarding lightening a too dark brown shade to a deep red. I read your tips and they were very helpful. Anyway this is what I did- I used a 3o vol developer and mixed a combo of Sunset Brown, Red Ginger and Coppertone together and did a strand test for 15 minutes. I liked the color after I dried it so I put it on. Well I panicked when it looked like the roots were turning to light so I rinsed after only 10min. Actually the roots turned out fine as did the rest of my hair but it still isn't quite right(not light enough or maybe not as red as I hoped) So I quess I wiill wait a few weeks till I need to color again, do another strand test and so how it goes. should I not put the color on the roots first because i am outside quite abit and that is the first part of my hair to lighten up. Thanks again for everyones help.Susannah