when i have my hair colored every 3 weeks the colorist uses a dark blonde 6.5 or 7 within a week i am a light blonde always. probably the sun, swimming, live in florida. my hair is also 95 grey white. hence im a blonde. what color do you recommend??? can i put the color all over every time?? or do i have to deal with roots. my white grey hair is very very resistant around my hairline also. tips????