Does green discharge with little or no odor mean infection?

Not necessarily: Color and odor don't nail diagnoses, but they do suggest them sometimes. If this is a vaginal discharge, this suggests maybe trichomonas infection. See a doctor for further evaluation.

Green Discharge: A green vaginal discharge is an abnormal feminine secretion that is often foul smelling and comes with other symptoms like itchiness, inflammation, pain and possibly fever. It is often caused by infection, but may also accompany other conditions where a secondary or overlying infection occurs. Diseases include: ginorrhea, trichomoniasis, clamydia, bacterial vaginosis. And pid.