Lightfastness
All paints are affected by light, the amount depends on the pigment the paint is made of.
Many online databases use a four-step scale that looks like this:
E = Excellent (Excellent)
VG = Very good (Very god)
G = Good (God)
F/P = Fair/Poor (Moderate/Poor)
Under real-world conditions, on a wall in a normally lit room, you can interpret it roughly like this:
E: Minimal or no visible change over several generations, over 100 years.
VG: Very little change over a long period of time. Maybe 50 to 100 years.
G: Noticeable change over 15 to 50 years.
F: Rapid change from a few years to a dozen years.
P: Can change within a few months to a few years.
Paints with a ranking lower than VG should be avoided.

