If Cathy put 6 pairs of black gloves and 6 pairs of brown gloves in her drawer in complete darkness how many gloves must she take out to get a pair?

I assume you mean a matching pair. If so, the answer is 13.

Considering the worst-case scenario, she may pick all six left-handed brown gloves and then all six left-handed black gloves. In which case, the next glove would definitely be a right-handed (black or brown) glove giving a matching pair.

Even in complete darkness, Cathy might be able to discern the difference between a right and left-handed glove (mittens not so much). So, as written, the answer is two. If we assume a matching pair, the answer is eight.