First time - stems turning purple and leaf discoloration- pics included

Looked great until about 3rd week. Did have a problem with FN and temperatures have dropped. Can someone provide some insight from pics possibly. Also any guesses on strain? Thanks.

How cold is it? Low temperatures will detrimentally affect the root system and the uptake of nutrients, particularly in the case of magnesium. What nutrients are you giving her? Is it just those leaves that are yellow? Can you take a pic of the entire plant? Might be a little easier to seen an overall picture

BUT truely purple stems are often caused by genetics. That doesn't mean anything is wrong with your plant.

The main stem is green. Those 2 fan leaves are the only ones that look off. I am using Sugaree for nutes. Have to take a pic tomorrow. She's sleeping.