Nope, nothing serious. But there is a tip that helps, especially Catts through the cooler weather. Add a little Epsom salts to your regular fertilizer routine. I put about a tablespoon in my 2gal. sprayer every few weeks.
If you see any reddish tinge on the leaves it is a magnesium deficiency. I must admit I thought that might be what your purple marks on that leaf were. Hard to tell, but a little extra magnesium can't hurt.
