The Elder Scrolls Online: Shadows of the Hist Interview had the opportunity to chat with an unnamed developer at ZeniMax Online about their Shadows of the Hist expansion to The Elder Scrolls Online, with a particular focus on the new style parlor being added to the game and the character appearance modification choices we'll have. A snip:

MMORPG: Will there be hair and other styles that are only available in the Style Parlor?

Yes, new appearance options can only be found in the Style Parlor, and we will add more over time.

MMORPG: When a player has collected a new appearance option, will they be able to use it again or account wide?

Once you’ve unlocked an appearance option, that option will be available to every character on your account in perpetuity. However, keep in mind that certain appearance options may not be applicable to all characters—a Breton wouldn’t be able to use an Argonian scale pattern, and an Argonian wouldn’t be able to use Khajiiti ear tufts, for example. While the Name Change, Race Change, and Appearance Change Tokens are account-wide, it’s important to note that these are single-use items. They are consumed when you finalize your new name / race / appearance.