Thanks everyone.
@dannyk13 - That is my answer as well, but I am worried that it may be too much of a stretch to get to that answer from the two symbols?
@JJ109 - I like that answer for the male symbol but what would the female be?
Just to be clear - THE OPPOSITE SEX wasn't a flippant answer to nickizzle's ''...but what would the female be'' it was what i think is the answer to the original question (the two sex signs are shown in opposite colours - black and white).