Stating that everything is not black and white is not moral relativism. It's simply the reality that you cannot delineate on most issues where exactly white becomes black. Some things can be easily said to be white and some easily black, but most issues are not clearly in one or the other. Gray does indeed exist in the real world.
The abortion issue is a case in point. Where does support for abortion in the case of rape, incest or life of the mother fall? What about morning after pills? What about those that support abortion only during the first trimester? Are they just as "black" as those that support abortion on demand during any period?
Yes. These positions can be wholly rejected. Abortion as birth control is without any merit.
Where does support for abortion in the case of rape, incest or life of the mother fall?
While I would argue these as well, for the sake of the argument, lets say these are gray areas... Given the vast number of abortions currently being performed, how much "Gray area" is there? I would suggest it is so minuscule as to be statistically moot.
Pretty black and white, I'd say.