A legal representative for Prince’s heirs warned corporations to respect the late artist’s rights or “suffer at your own peril.”

Entertainment lawyer L. Londell McMillan spoke out after beverage company Bang Energy failed in a bid to trademark a product range called “Purple Rain.” A U.S. Patent and Trademark Office tribunal ruled last week that the brand was indelibly connected with Prince, agreeing with McMillan’s position that the phrase was “uniquely and unmistakably” associated with his legacy among the general populace.

“‘Purple rain’ is not a word in the English language,” Prince’s estate’s filing read.

“Prince chose the phrase and made it famous through a Grammy-winning album, a major motion picture, a song performed around the world and the iconic image of the late artist in the costume, movie and tour. For the great majority of consumers, the only significance the term ‘Purple Rain’ has is to identify Prince and the image he made famous.”

In its ruling, the board wrote, “It is commonplace for performers and owners of well-known marks to expand their product lines, in order to incorporate a diverse set of goods to capitalize on the renown of their names and brands.” As a result, it was likely that consumers would make a connection even if a product had “no relation to the reason for the celebrity’s fame.”

Bang Energy CEO Jack Owoc told Billboard he was a “big fan” of Prince and added, “We greatly respect Prince and his estate and will not ‘rain’ on their parade. Maybe we can negotiate a deal in the future that is mutually beneficial to both parties.” “Prince’s music, art and trademarks hold a special place in our society and culture,” McMillan said. “Purple Rain is a Prince mark and brand known worldwide. Please respect these unique assets or suffer at your own peril.”

A legal case concerning a Purple Rain wine range has yet to be concluded. Its makers argued that consumers would not make a connection with Prince because he didn’t drink alcohol.