To visually identify which account each email belongs to, you can assign a unique color per account. This color appears in the Unified Inbox per mail and helps distinguish between Read (empty) and Unread (filled) states.
You can easily change the Account's color.
- For desktop users, go to Settings | Account Settings | tap the account you want to update | Account Color | Choose a color and OK.

- For mobile users, the steps are slightly different:
Go to More | Settings | Account Settings | tap the account you want to update | Edit Account | Account Color | Choose a color and Save.
