Overlay ain't such a good layer mode for a c4d, Try screen for effect c4ds, normal for render c4ds but try smudging it a bit for a better look. When using a c4d, make sure your background has some sort of effect already, it can't be a black and white background and a c4d added, That usually messes things up, Try getting good with smudging, then add a c4d on top of the smudging, you'll see, it'll look better 
