Aio is not allowed to use the color for advertising and marketing in stores, on websites and social media. The decision was made after a three-day hearing. The court sided with T-Mobile's position that it is identified by the magenta color and that such use of the magenta color is protected under trademark law. AT&T has already announced that once its deal to buy Leap Wireless closes, it will drop the Aio name anyway, making the ruling not as important for AT&T as it might have been otherwise.
We would also like to point out once again, the absolutely hilarious tweet that T-Mobile CEO John Legere sent out on the day that the suit was announced last summer.
source: T-Mobile via TmoNews