In the early days of its existence, decorators and their suppliers were the main customers for Dulux, with Say Dulux to your decorator used as an advertising slogan in the 1950s. By 1953, Dulux was available in the retail market and ten years later the famous Old English Sheepdog was used in advertisements, to the point where “Dulux dog” has become a common nickname for the breed. The name Dulux is derived from the words DuPont and Luxury.

Info gleaned from Wikipedia