A Blue always answers a question truthfully; a White always lies; a Pink, answering two or more questions, tells the truth and lies alternately; his first answer, however, may be either truthful or otherwise.

A visitor to the islands approached a group of three natives, whose names were Mr. Pink, Mr. White, and Mr. Blue. One was known to be a Pink, one a White, one a Blue.

Taking Mr. Pink aside, the visitor put some questions to him.

“Mr. Pink,” he said, “are you the Pink, the White, or the Blue?”

“I am the Pink, sir.”

“And Mr. White?”

“He is the White.”

“So Mr. Blue is the Blue?”

“Obviously.”

Is Mr. Blue the Blue? If not, what is he?