Outfits in Final Fantasy 7 Remake are sets of unique clothes that can be worn by Cloud, Tifa and Aerith. Throughout the game, 9 outfits can be unlocked which changes the appearance of the playable character. These do not grant defensive properties, effects or change the stats of the character, but is only used for cosmetic purposes. Outfits can be acquired through the game by either completing quests, meeting certain criteria or provided as extra DLC. This page indicates a list of all the unlockable Outfits in Final Fantasy VII Remake.
Final Fantasy VII Remake Outfits
Like Aerith, the outfit that Cloud wears in the Honeybee depends on the amount of Side Quests you complete in Chapter 9: The Town that Never Sleeps. If you don't complete any Side Quests you will get the Black Dress, if you complete Burning Thighs, The Party Never Stops and A Dynamite Body Side Quests you will get the Blue Dress. To obtain the Purple Dress you need to complete the quests Burning Thighs, The Price of Thievery and Shears’ Counterattack.
After you complete all Side Quests in Chapter 3: Home Sweet Slum you will be able to meet with Tifa at her room. You will have to make a choice between three differnt outfits: Mature, Sporty or Exotic. This will have an impact in Chapter 9: The Town that Never Sleeps.
After you finish the game you can re-play Chapter 3: Home Sweet Slum to change the outcome, but make sure you complete the whole chapter so it takes effect. From here, you can just skip to Chapter 9: The Town that Never Sleeps and watch the change.
The dress that Aerith wears during Chapter 8: Budding Bodyguard will depend on the amount of Side Quests that you have completed for that chapter. If you don't complete any quests you will get the Discrete Pink Dress, if you complete 3 - 5 you will get the Normal Pink Dress and if you complete all side mission you will get the red outfit.