JoeyGonzanswered grow question 4 years ago The change in color is generally attributed to the appearance of anthocyanin, a water-soluble pigment that plants generate either due to their genes or due to potassium deficiency, and low temperatures can also mess with color. Sometimes your plants might trick you, showing colors due to nitrogen excess and you end up thinking that the color change is due to its genes. Test your soil to be sure