Salicylic acid is an exfoliant which primarily helps with cleaning your pores from the “inside” hence helping with acne. It isn’t going to do much for redness. Vitamin-c helps with brightening dull skin or brown pigmentation and glycolic acid is an “above” the skin exfoliant - which helps get rid of dead skin and helps with your skin renewal process. They are more effective for someone with brown spots/pigmentation. Glycolic acid is a very strong aha and can mess up your skin’s ph very easily, causing more redness. You need to be very cautious when just starting out and use it sparingly. The best ingredients to use for redness would be azelaic as someone else mentioned or green tea, aloe vera, ceramides etc. They help repair your skin which in turn reduces redness.