Are you adding grain in a diff program or something? Cause i add grain in after effects on an adjustment layer above the main files. So i can adjust the separate elements independently. You can also change its opacity and other stuff to the grain then. You could color grade the grain this way too if you wanted. Or noise. If i add grain through another video overlay or something, then it doesn’t look as good.
Sorry for the late reply, I’ve just been using Premiere Pro. I dunno much about doing effects.