Post Processing Neglect Particle Systems

Hello all,

I’m trying to develop a scent mechanic in a game I’m working on. When the scent mechanic is being used, I wish for the entire world to go into greyscale with the exception of scent trails left behind.

I have the scent trails working. They’re the default UE4 dust particle effects, left behind in trails. I’m not sure, however, to get these to not go into greyscale with the rest of the map when I apply the post-processing effect to the map.

When I look this up, I see mention of using custom depth, but I’m not really sure how I’d use custom depth to allow it to ignore the post processing greyscale effect.

Does anyone know how to neglect just a list of particle references from changes to the global post processing effect volume?