talks and leaf stem

hey guys could anyone tell me why my plants that are in first week of flowering the stalkes and leaf stems are purple but the plants look fantastic growing very well and they look to be very happy

some strains have that colour thru them other times its to do with temps dipping in veg. wouldnt worry about it.

Quite common dude, could be many things.
Colder temps, phosphorus deficiency, genetics
I wouldn't worry if they growing well and look healthy apart from the stems