How to alleviate hyperpigmentation after laser hair removal treatment?

Had a few sessions of laser hair removal for my lower legs and underarms for the last half year. Although it worked well for my underarms, my legs are normally left with red swollen spots for a week after each session, and I am advised to apply steroid cream for the next 3 days. The swelling and itching will subside eventually but my legs look bruised and has dark spots even after applying liposomal serum for 2 whole months. What can I do to treat the dark spots?