Xanthophyll is a plant pigment, of formula C40H56O2, responsible for the yellow and brown colors of leaves in autumn. Chemically it is a carotenoid, a group of compounds that includes carotene, another pigment which gives the red color to carrots and tomatoes, and which is found with xanthophyll in most green plant material. All carotenoids, including xanthophyll, also play a part in photosynthesis.
Xanthophyll consists of two isomers, lutein and zeaxanthin, which are oxidation products of α and β-carotene respectively. The term is also applied to encompass most hydroxylated carotenoids.