I would look into the strain and make sure the purpling isn't genetic. If it isn't genetic you may have a phosphorus deficiency and some times to much direct light to stems can cause red to purple.
@Oscar Quintero Well @mwhite9829 took the words right out of my mouth lol. You plant looks pretty good overall. If you worry about the leaves been too dark and shiny (signs of nitrogen toxicity), you can just feed water the next few times the soil dries out.
I would look into the strain and make sure the purpling isn't genetic. If it isn't genetic you may have a phosphorus deficiency and some times to much direct light to stems can cause red to purple.
Can you please take a pic in normal lighting? All we see is purple. Also please include more info. This post tells you what to include: https://www.mrgrowit.com/forum/grow-community/read-me-first