I saw this movie in the late 80s or early 90s. It seemed to me to be a sci-fi horror genre. I remember some sort of scientific group or military group were isolated. Either on a spaceship or a boat or a compound in the middle of nowhere. The point was they couldn't get away quickly.
When people were alone, this red mist would wait for people to be alone and then kill them. I do remember one scene where some guy was cleaning a bathroom or a locker room and it came for him.
Possibly Invasion from Inner Earth (1974).
From IMDb:
A group of young pilots in a remote region of the Canadian wilderness begin to hear strange reports over their radios about planes crashing, cars stalling and a deadly plague which has gripped the planet. It becomes clear that earth is in the midst of an invasion. The group of pilots decide to barracade themselves in a cabin deep in the woods and wait for their impending doom.
Specifically, from this review:
After some red mist appears and people begin falling dead in the street, we cut to hunter Jake and his sister, who were putting up three students who are now ready to return to civilisation via plane. However, once heading for the airport they are prevented from stopping by a sick man who then collapses on the runway.
Several other reviews mention "killer smoke bombs", "colorful smoke bombs", "smoke bombs and flashlights with red cellophane" and the like.
Found with the Google query scifi movie red mist site:imdb.com/title.
