<P> Chromoplasts synthesize and store pigments such as orange carotene, yellow xanthophylls, and various other red pigments . As such, their color varies depending on what pigment they contain . The main evolutionary purpose of chromoplasts is probably to attract pollinators or eaters of colored fruits, which help disperse seeds . However, they are also found in roots such as carrots and sweet potatoes . They allow the accumulation of large quantities of water - insoluble compounds in otherwise watery parts of plants . </P> <P> When leaves change color in the autumn, it is due to the loss of green chlorophyll, which unmasks preexisting carotenoids . In this case, relatively little new carotenoid is produced--the change in plastid pigments associated with leaf senescence is somewhat different from the active conversion to chromoplasts observed in fruit and flowers . </P> <P> There are some species of flowering plants that contain little to no carotenoids . In such cases there are plastids present within the petals that closely resemble chromoplasts and are sometimes visually indistinguishable . Anthocyanins and flavonoids located in the cell vacuoles are responsible for other colors of pigment . </P> <P> The term "chromoplast" is occasionally used to include any plastid that has pigment, mostly to emphasize the difference between them and the various types of leucoplasts, plastids that have no pigments . In this sense, chloroplasts are a specific type of chromoplast . Still, "chromoplast" is more often used to denote plastids with pigments other than chlorophyll . </P>

A pigment not found in plastid but dissolved in cell sap