bud Yellow leaves are a sign something is off for sure. I would check the Ph, ensure you have not been over/under watering, and especially watch for nute burn. I don’t think it’s temp/light burn because you have it on lower foliage as well. Too much nutes seems to be the culprit often.

DannyPH Auto Flowers automatic starts dying at the end of its lifecycle. This looks normal for the time period you’re in. She is literally using all of her own resources to finish out, thus leaves start turning yellow.

CraigBengfort I agree with Danny you’re at day 70 you should be coming pretty close to harvest and it’s normal for the plant to cannibalize it’s leaves to work on buds

himnherbs