Do smoke bombs stain?
A more involved blog post that would require using white fabric pieces to test the distance required to not stain clothing. This is top google search for smoke bombs. Would also be a good Pinterest pin.
Outdoor images of white cloth (perhaps cotton) and how close you can be to a smoke bomb without staining. A disclaimer that the photos are of cotton and we can't speak to how more delicate fabrics would react (wedding dresses etc).