Purple stems

I believe that this is just because of the strain, but my partner is worried we may have a bigger issue. This was a clone planted in the middle of June into royal gold soil. I'm going mostly organic while I do add very small amounts of bud candy and other various advanced products because I have them at my disposal. I feed them advanced every other watering. Sometimes longer and I'm never feeding over 25% strength. The strain is a mystery strain. It was labeled "SSD" and I was told by a friend (unreliable source) that is is super sour diesel although SSD doesn't match up with SDS. I don't think SDS has purple stems either. I uploaded the second picture so you could see the structure and fan leaves of the plant more to better identify what I may be dealing with. Any help would be much appreciated.

Looks normal to me. Cool nights will bring out colors.

Looks like some yellowing at the bottom.

Usually it's because of genetics, but if you start to notice other problems with the plants, then it could be because of deficiency. In this case it just seems to be from genetics.

that's very normal and common in many many strains and it doesn't indicate purple flowers

Your plants look hungry my amigo.

Nothing wrong with purple stems most times.