my car is black cheery, could i change the color to jet black without re priming the car? or any other dark color?
You could depending on how old the existing paint is but...I wouldnt.You risk bleed through of the underlying color when applying your new topcoat.
If you stick with a dark color like black and there isn't any deep scratches (if there is just repair them and use black primer) you should be ok.As long as the paint job you are painting over was prepped well.