As to the phrase, according to the website Cat-ch Phrases, "The Cat's Pajamas" means:
"something considered to be outstanding. The term "cat's pajamas" comes from E.B. Katz, an English tailor of the late 1700's and early 1800's, who made the finest silk pajamas for royalty and other wealth patrons."
The King favored Katz pajamas for the fine color and silk.