Tim Bullock tweets and asks:
I’m adding floating Dust Particles in AE for a Music Video. Should I grade before or after VFX? @cineblur #decisions
— Tim Bullock (@Tim_Bullock) January 31, 2013
Color grading after visual effects are added will make the effects seem like they are seamlessly integrated in the scene. You might have to correct your VFX a bit before the grade to match the original footage’s white balance, exposure, etc, but when you add a visual effect such as particles or flares, adding an overall color grade after they are added will make them seem more realistic and lifelike.