Dark shiny waxy leaves?

Hey mate, purple stems can be a genetic trait. They can also be due to stress, I noticed mine turn purple when I give them too much light. Check on them an hour before lights out, if they are still like this you can rule that out. As the drop their leaves when theyve had enough. They are looking pretty dark, this can be a sign of a little to much Nitrogen. I can see on one leaf there is a little but of discoloration which seems to be inline with a calcium deficiency. This could be due to a little too much nitrogen. Hope this helps 🙂