Although not part of the original motifs of the Yellow Mythos, several of the stars associated with it are red and related non-mythos fiction has made use of worlds with red suns. Such a red sun is likely to be a red giant nearing the end of its life-cycle and is fitting for worlds implied to be ancient and dying. Examples include:
- Aldebaran is a red giant star.
- The Hyades contains red giants.
- Betelgeuse is a red supergiant star.
- The star orbited by the world of Darkover is a small red star older than our sun.
- The far future earth of the non-mythos story Earth's Last Citadel is illuminated by a dull red sun.