Hi growmies i would apreciate it ur opinion

The pictures dont help, cant really see the stem. But it guess its the genetic, since the plant isnt dying and buds/leaves looking dark too, if it would be rot on buds or roots your plant would be dead or struggling hard rn, but shes fine👌

Where are the leaves? Maybe, keep some of them next time, lol. you ask about stems but not zoomed in for pictures? the purple in the leaves is probably cool temperatures at night. Looks like dark buds, but that's genetics. petioles turning dark red is not unusual under LED. If the trunk is red, that could be a sulfur deficiecy or simpyl genetics... with the purple/dark buds i'd lean genetics. if soilless/hydro calculate S ppm and if it's 100 or more that isn't the cause in more cases than not.

with no diary hard to pin point where things would have went better. I see small pots and then in turn small plants. I think you would increee your pot size and get better results from that alone. I am sure there are other area to improve on but again with no diary hard to say.