As autumn arrives, leaves on many species of deciduous trees change color until they are eventually severed from the tree by a special layer of cells. These vibrant colors are brought about as trees slowly produce less and less chlorophyll, as it is more costly to produce than its worth in months when water and light are in shorter supply. As the green pigment fades, other pigments that have been hidden underneath emerge. Xanthophyll is visible as a yellow color; carotenoid an orange color; and anthocyanin a red color. These are all present in spring and summer as well, but are outnumbered by the green chlorophyll.