There are two major groups of pigments in fresh tea leaves: chlorophylls and carotenoids. These pigments condense during withering and oxidation and become darker. During oxidation, the green color of tea chlorophylls is converted to black pigments known as pheophytins. This conversion leads to the dark appearance of finished oxidised teas. Tea carotenoids are another pigment group found in tea leaves and are mainly composed of carotenes which are orange and xanthophylls which are yellow and are also responsible for the color of finished tea leaves.