Is this normal? Or what does it mean?

[Cclem85]

So I just went and checked on grow #1 and spotted some redening of the leaf stems, is this normal? Or if not, what does it mean? Thanks in advance!

 

[Clancy]

I get red streaks/stems/spots here and there...I don't worry about them and I don't think you should either. I've only grown a few times but so far always with satisfactory results. Someone with lots of expertise may offer you other info about deficiencies that can cause red stems. I don't see that kind of thing on yours though. Anyway it's not life-threatening to your plant..if that's your only issue throughout your grow then I think you're doing fine---nice healthy looking leaves and colour