Red Stems

Hi guys

I am in South Africa and it is currently winter here. My plants are indoor under lights.
Why are my stems red even though the plant seems healthy? See attached.

it must be that good african shit

i got the same problem, my main stem isn't as red as the pic you posted part of the stems are showing a reddish/purplish color. so im interested to know if thats a good or bad thing.