i dont see any red in the leaves just light green. A little red on the very bottom of the stem. whats the info on the grow? lights, food etc...? How old is it? seems like its had some problems
Red color is usually from Anthocyanin, the same red color in beets. It's usually from colder weather. I beleieve it's an adaptation of the plant to combat colder weather. You sometimes see it in broccoli and 0ther vegetables during colder periods.