Colours out of Space

The Colours out of Space are basically just that—a colour. Most representations I've seen convey this as a form of vapour, though it technically isn't. To quote the story, a Colour "sucks the life out".

In the RPG...

Colours are almost more of an environmental effect than an enemy that can be combatted. When the colour feeds—via an opposed POW roll—it drains an average of 5 points from STR, CON, POW, DEX, and APP, on top of an average of 3 hit-points. They also weaken the minds of anyone nearby—via a daily opposed INT roll—whereby the victim loses an average of 3 magic and 3 Sanity points. A Colour cannot be harmed with any form of weaponry, though a magnetic field can contain it, and magic (that affects stats rather than hit-points) can also affect it.

In a video game...

I think a Colour out of Space would work in a game if it was treated as an environmental effect around the one location.

In a film...

There have been a few adaptations of The Colour out of Space, including one as recently as 2019, though I've yet to see one that really does the story justice.