Anthocyanin

Pigment within grass leaves which can be produced during times of plant stress. Different colourations can occur, with a blue, purplish or reddish tinge being common. A deficiency of phosphorus commonly leads to a purple tinge to a leaf. High, low or changing levels of light, especially during colder periods leading into the autumn, can all contribute to the production of anthocyanins. The use of supplementary lighting could influence, by increasing, the anthocyanin content within grass leaves, giving an inference of a nutrient deficiency when one does not exist.