In various embodiments, a method of providing a hair treatment agent is provided. The method can have a detecting of at least one sensor value on hair of a user by employing at least one portable sensor, a determining of a hair condition of the user by employing the detected at least one sensor value, a computer-assisted determining of a user-specific hair treatment agent including the determined hair condition, and a preparing of the determined user-specific hair treatment agent by employing a hair treatment agent mixing device.