Shagrathanswered grow question 4 years ago Hi there!
This kind of purple in the leaves is molybdenum deficiency BUT this is also totally normal for some plants during the end of their growing cycle and nothing to be afraid of.
The plant also troubles to use molybdenum in colder temps so that's why for example cold nights brings out the purple color better. Also too much Sulfur will lock out Molybdenum
But I would not worry about that 'cos it looks pretty normal to me.