ok i would stay away from any scented oils and things because that can cause a serious infection. i would most definitely keep it as moist as you can like a warm wash cloth. it looks black because of dried blood and most of the time the stitches are black. also if you are concerned about a scar get vitamin e gel caps and pop it will a pin and rub the vitamin e oil on it.
first thing you should do is stay away from the stiches till they are removed. dont do anything now, once it is removed that you have to leave the place like that for the next 15 days like that only, than with in six months you can use any of the creams whicxh doctor will prescribe to minimise the look of the scar.