Copying a comment that I left below just because it addresses this too:
The game has several different “costume types” (casual/home wear, show wear, formal wear, and swimsuit wear), and each of those costumes has different hairstyles/dresses associated with them! The casual/home wear (which is the first one you wear) only has one option for hairstyle and dress just because the MC doesn’t care too much about dressing up at home 😂 but the other outfits have more options!
(Originally the home outfit wasn’t going to be customizable at all to be honest, but I thought it would be good to at least let people customize the colors 😂)