Could smoking discolor invisalign?

Probably not....: You will be changing your aligners every 2 weeks so smoking will probably not stain them. Cleaning them thoroughly when you clean your teeth every day will help prevent staining.

Slightly: Although trays will discolor slightly, you will be changing them every 2 weeks. Problems include, however, trapping smoke between the trays and the teeth, accentuating tooth discoloration, and the normal damage done by the toxins in the smoke to all of your soft tissues. This might be a wonderful time to consider quitting. Good luck.

Yes: Smoking while having invisalign on is not recommended and can discolor the plastic.