A squabble over who stole the magic marker seems more fitting for a classroom than a courtroom. But a federal judge has sided with T-Mobile in a recent trademark lawsuit, saying that Aio Wireless, an AT&T subsidiary, isn't allowed to use colors resembling T-Mobile's promotional "magenta" color.

The Texas court has ordered AT&T to stop using Pantone 676C, a.k.a "plum," over fears that it might cause consumers to confuse the two brands. According to the presiding judge, T-Mobile successfully argued that letting Aio continue to use a variant of magenta would cause it irreparable harm.

In a statement declaring victory, T-Mobile called AT&T's actions a "transparent effort to infringe" and that the court rightfully defended T-Mobile's sole ability to use the color magenta.

A spokesperson for Aio, Alejandra Arango, said the company has already given up using its controversial color of choice.

"While we disagree with the court's decision, it addresses advertising and store designs that we are no longer implementing. Accordingly, this decision has no effect on our advertising plans," Arango said.

T-Mobile's claim stems from its parent company, Deutsche Telekom, which in the 2000s trademarked a pinkish hue known as RAL 4010 for its promotional campaigns. A side-by-side comparison back in August showed that what T-Mobile argues is "magenta" seemed pretty distinctive from the wine-colored tone that Aio used. In fact, T-Mobile's definition of magenta appears to have expanded beyond its original trademark; rather than owning a specific shade of pink, the company is now claiming nearby colors, as well.

With due respect to the importance of trademarks, if there were an Academy Award for silly lawsuits, this one might qualify. After all, few things speak more loudly than price and service quality — characteristics of a business that tend to transcend marketing materials. Promotional colors can engender valuable feelings of trust and loyalty, to be sure. But I'd wager the share of Americans who select their wireless carrier on the basis of their favorite color is pretty small.