Okay, so I dyed my hair yesturday night cherry black, & it's not really the colour I want, I want to be redish brown.. so if I get a redish brown dye and go over it today will it mess up my hair?

What shape is your hair in? Don't do anything more to your hair until you get it in good shape.

I would suggest using a good color remover before proceeding with any additional coloring. Oops works pretty well.

It will probably dry out your hair and cause some ruff hair. If you do you might want to use color stay shampoo or shampoo that prevents dry hair. Otherwise goodluck :)