AIUI, it was Coca-Cola's advertising executives who decided to to give the Nast-style "Santa" his red and white suit -- to match their logo.

And yes, I remember reading that Moore might have stolen credit for "A visit from Saint Nicholas," but I can't remember the details about that.

In any case, that "right jolly old elf" certainly wasn't wearing red -- "He was dressed all in fur, from his head to his foot," and "was covered all over in ashes and soot." Unless there is a fur-bearing mammal with a berry-red pelt out there in the world, somewhere, that makes me think "Moore's" Santa was wearing a mixture of browns, greys, and perhaps whites.