Materials frequently undergo discernible color changes and surface degradation when exposed to sunlight and ultraviolet radiation over extended periods due to photochemical breakdown.
The claim is specific and empirical, addressing whether materials change color under prolonged sunlight exposure. Papers 2, 4, and 5 all directly evaluate material degradation and color changes resulting from ultraviolet irradiation or weathering, providing robust support for the claim. No papers contradict the claim.