It is common for acne to leave acne marks, one is brown or light brown, you can use topical creams, such as those containing salicylic acid or retinoic acid, to apply daily to increase the metabolism of pigment particles to reduce acne marks. You can also use fruit acid peels once every three weeks to reduce acne marks, and red acne marks indicate mild inflammation and small capillary dilation, so you can use anti-inflammatory creams, such as fusidic acid, and strong pulse light or laser for blood vessels to close them to reduce red acne marks. For acne pits, also called depressed scar, the role of drugs is very limited, so the most effective treatment for depressed acne pits is called fractional laser, fractional laser has 2940nm erbium laser, ultra-pulsed carbon dioxide fractional laser, etc., through 2-3 months to do once slowly to smooth the depressed acne pits.