The Model 60 was originally made with the front sight integral with the barrel, so changing the front sight is impossible without changing the barrel. Alternatives are to simply paint over the red, or to drive out the dovetailed red insert and make a new one from the appropriate steel, or from plastic of whatever color you prefer. If the sight is pinned in, you can obtain alternate ones from S&W, and I suggest sending the gun to them for the work, or from Brownells.
Jim