How to make a gun spray paint/gel-like substance?

I want to make a script for a game i’m working on that spays a paint-like substance of any color I want (kinda like splatoon.) The liquid also must be slippery and stick to walls/floors. But not to ceilings. (It’ll just drip off ceilings)

i would use a particle effect that look like the spray and interact the wall + an invisible sphere you shoot
when the sphere hits something you apply a decal to it.