More information has been unearthed about smoling jackets.
Since they originated in the Victorian Era, the preferred fabric used for smoling jackets was, and is, velvet. Burgundy and forest green were often seen, but the preferred color was, and is, black, mostly because it shows off the accumulated dirt and mud, which is highly desired.
In fact, in the decades since, some owners of black velvet smoling jackets have taken to highlighting the mud and dirt with paint, even to the extent of painting designs and patterns on their jackets. Rock legend Elvis Presley was a long-time fan of smoling jackets, and had his painted with portraits of himself, which of course created an entire ancillary industry.