T-Mobile wins fight for magenta against AT&T's Aio Wireless

T-Mobile has won its battle over the color magenta, with a federal court ruling AT&T's subsidiary brand Aio Wireless must cease using the distinctive hue. The case, filed back in August 2013, began when Aio Wireless – which targets cellphone users looking for prepaid or contract-free plans – started using large blocks of what it referred to as "plum" color in its advertisements and promotional materials.

T-Mobile unsurprisingly felt the colors were too similar, and accused Aio Wireless – and AT&T – of trying to infringe on its "trademark" color. "Aio does not use the orange coverage map of its parent company," T-Mobile pointed out last year, "but instead uses in its stores and on its website a magenta coverage map that is strikingly similar in color to the one used by T-Mobile."

Now, a Texas court has agreed with the carrier's argument, after each side set out its respective case over a three day hearing and extensive argument beforehand.

Aio Wireless must cease using either magenta or any similar colors in any of its marketing and advertising, the court ruled. That includes in-store, online, and in any sort of social media. Wireless customers identify T-Mobile with magenta, it was decided, and thus the carrier's use of magenta is protected by trademark law.

The ongoing battle between T-Mobile and AT&T has ramped up in recent months, primarily down to outspoken T-Mobile CEO John Legere, who hasn't been afraid to call out his rivals by name.