Beyond the initial customization screen when you start the game, you will need to reach a point in the story where you'll meet a character named Tallow. She will be south of your main camp, near the beach. Beside her is a closet that, when clicked, will allow you to customize your Scout's appearance including your eyes and skin color.
You can also view, stash, or grab any clothes in your collection using the closet. As you further progress the story, you'll also receive a mannequin which you can dress up to assemble the outfits you want to wear.
All types of clothes are available for all Scouts to wear, so be creative and wear whatever you want!