Re: black, black color, etc.
A and D are both grammatically correct. The "in color" in D is not necessary but it doesn't make the sentence incorrect. B is wrong. C would only work if there were various different shades of black involved and you went on to say something like "...a black color, a sort of dark-grey black rather than a pitch black, if you know what I mean". In the context given, C is incorrect.
Originally Posted by maoyueh
Remember - correct capitalisation, punctuation and spacing make posts much easier to read.