It's too late to call the 800 number on the box! I colored my hair 24 hours ago but don't like the color and was wondering if it would hurt if I colored it again this soon?

It is not a good idea.
My daughter did that and was okay though.

I've attempted to dye my hair blonde one time and it came out red so the next morning I dyed it back to my natural hair color and it was fine.