should i dye my hair again? Options

[cloudcandy]

okay my hair is naturally black, I've never done anything to it like perm or bleach. So last year May, I dyed my hair black because I have gray hair(I'm young I know, it runs in the famz) then in August I dyed the back of my hair red. I want to dye my hair back to black in Feb for a formal party that's in Feb. Should I dye my hair again? the red dye I used in my hair was a Clairol product, I can't remember the exact name but it says it washes out with 28 washes and it's for people with natural hair and it has no ammonia in it.