This morning I noticed some branches on my young plants had turned reddish on top.
Last night the humidifier ran out of water and RH dropped to 40% overnight.
Could this just be a stress reaction to that low RH, or sign of a deeper issue?
Some strains will have red stems as a genetic feature.... and it's usually the purple strains... I wouldn't worry about this on your plant - I think they're naturally red.
Good luck!