The different types of plastids leucoplasts (colourless), chromoplasts (coloured), chloroplasts (green coloured) such as are interchangeable. The transformation from chioroplasts is observed during ripening of fruits (e.g.,Tomato, chilli) when they change their colour from green to reddish orange. It takes place through loss of chlorophylls and degeneration of lamellae. The most common carotenoid of the fruit is lycopene. Petals of Calendula develop orange yellow colour due to the formation of chromoplasts from proplastids. Carrot root develops it characteristic colour because of the conversion of leucoplasts into chromoplasts. It is rich in carotene.