Darker colouring

Genetics and environment expressing purple buds!

Id say u haven't really got anything to worry about I've Just finished 2xnorthen light autos and to look at side by side u would say different strains...I was on the worry until I seen pics of other people's n.lights and realised each were different in their own rights...so Imo genetics but document everything down so if u hit a problem on future grows u have ur note book to look back at good luck Craghodgy 💨

Looks like your calyxs are growing out purple. It’s genetic, and not something caused by any kind of deficiency. I grew a devil cream that looked like that and continued to darken for the rest of her flower. 🌱

I assume you mean in the bud site not the leaves - and that’s totally fine and normal. Just some expression of certain genetics with the dark color. If you’re talking leaves.. they also look fine. Don’t worry about that unless they are dark green with some heavy glossiness to them - that would be indicative of Nitrogen excess

Nah looks good - I have 2 x NL at the moment and one was so dark I thought continual N tox but it's budding heavily and never had a single issue :)