It's understandable to have a change of heart regarding what you want your character to look like in RPGs, and Diablo 4 is no exception. Though you may have thought that that hair color looked cool in the character customization screen, seeing it in action while you fight baddies makes you realize that it just doesn't fit right.
Unfortunately, Diablo 4 leaves much to be desired in the realm of character customization in-game. Most of the customizable options available in the character creator are set in stone once you create your character and, for some reason, cannot be altered after the fact. However, you do have some appearance options available to you, so here's how to change them.
Where Can You Change Your Appearance
Your appearance can only be changed in one place, the publicly accessible Wardrobe, which can be found at the top left of Kyovashad, the game's central city, that you gain access to after completing the tutorial.
Go to the marker seen in the map above, and after going up to the second floor via a ladder, you'll see the Wardrobe on the right-hand side of the adjacent room, opposite the Stash. Interact with the wardrobe, and cycle right to the tab labeled 'Appearance.' This is where you'll see what you can change.
What Can You Change
From here, it's as easy as changing what you like among the options available to you. You can change your make-up, your jewelry, the markings around your body, and the markings' color.
It makes sense, from a realism standpoint, that you can't alter your skin tone or overall body shape (even though some games do allow it), but, surprisingly, you can't even change your hair color or style, a customization option that's probably more realistic than removing and altering markings around your entire body.
It's unclear why Blizzard limited the post-creation character customization options so much, but unfortunately, this is all that's available for now. Players have pleaded for the post-creation appearance changer to be just as robust as the character creator, so this could be coming in a later patch, but we'll just have to wait and see.
When you're done making your adjustments, be sure to click Save Changes as you exit. Otherwise, the combination of changes you made will be lost, and your character will revert back to how it looked before.