I haven't seen benzoyl peroxide (or anything else) discolor lips. If it could, the color change wouldn't be permanent, anyway. You may indeed be overanalyzing your lips, out of concern. See a doctor if you're still anxious, but I see no reason for you to shift gears if the benzoyl peroxide is still helping your acne.
Take care.
Dr. Rockoff
Any suggestions for my continued discoloration Dr.I am extremely insecure about it and am thinking about a laser treatment (ugh expensive).