I actually think the grey has the opposite effect, makes the post really stand out and i go out of my way to high-light and read it, if only to see why the person was downvoted so much.
To stay on topic I can't believe the guy still hasn't apologized. Judging by his attitude and replies he's probably too busy self-rationalizing about how he's right and if everyone else wasn't an idiot we would all agree with him.