Green Dot, White Cup Still Art to Starbucks, Despite Being Told No

Starbucks Corp. has spent nearly six years trying to convince the Patent and Trademark Office that a white cup with a plain green dot is a distinctive design — and therefore warrants trademark protection.

The chain’s most recent design launched in 2011, when it simplified its black and green circular emblem. Its cups now feature its iconic siren carved out of a green circle without lettering. But now the coffee chain is arguing that it should have control over an even simpler design on a white cup—the green circle itself.

The trademark office isn’t buying it.

Starbucks’ bid to broaden ...