The bright colours and scent of flowers attract us. The fragrance of a flower is due to the presence of essential oils in its petals. These essential oils are complex substances. They produce volatile oils which keep on evaporating. The vapour of these volatile oils is fragrant in nature. This is the reason why we can smell the sweet fragrance of flowers. The colour of flowers is due to the presence of colour pigments in petals. One of the main pigments responsible for the colour is anthocyanin.