All they did was help solidify it as "the Santa look" I was born in 80 and raised by my grandparents who were born in the early 30s. They had some old Christmas decorations with a blue Santa and a green Santa.

Coke ran with the red Santa because it matched their company colors (red woth white trim, and red with white letters) and they made it the more popular color pattern for Santa, but in no way created it.