Paint or Obscurant
Paint, or more general obscuring fluids can be loaded into a Sprayer. This is very common for Industrial applications to apply paint quickly to the structures, or anything else requiring paint.
Rarely, in Solaris VII, paints are used in combat via Fluid Gun or Vehicular Flamer. With some luck, these paints can block the sensors of an opposing 'Mech, making it harder for them to get a lock onto their attacker.