If I were planning something different with my hair and had events where being seen and making impressions goes with the territory, I would give myself time for a test run, having it done at a salon you're considering. That way, if something goes haywire, there is time for your hair to recover and get it redone.
I am glad we were between semesters this past week, or I would have gone around with a paper bag over my head. I've been going to a salon for awhile where they do weaving really well, but the last time, the girl was on the cell phone while cutting my bangs.
They came out weird and short. I said, uhmmm, can you wait on these calls before the bangs were whacked.
Angry, I tried a new place, for weaving. My hair came out blothcy, down right odd. I went back, it was redone, but now I have to get it reconditioned.
Good luck with your coloring.