This has been discussed recently in the discord (the official translation of the necronomicon from greek to latin tales place in yhe game's time frame, most likely as a knock on effect of the 4th Crusade). The issue is that yhe Cthulhu mythos maps imperfectly to the 4 realms of ArM.
A story like the colour from out of space is a very neutral ine: a magical aura forms and gives people massive warping.
The Curse of Yig is more in the infernal direction, though faerie could be considered.
Cthulhu doesn't care as he lies draming, which is more magical, though his worshippers commit evil acts are infernal.
The Horror at Red Hook is racism, though it could be an infernal cult.