Thinking of things not specific to the Williamsburg Inn but to Colonial Williamsburg itself, the fife and drum corps play a big role in setting the tone. The junior corps is usually outfitted in off white hunting shirts with buff colored breeches. The senior corps usually wears the uniform associated with the 2nd Virginia regiment - red coat with blue facings with buff-colored waistcoat and breeches (the military would have the opposite - blue coat with red facings).
Cressets are used at night to light streets.
Lanterns are used to light outside stairs and walkways and are also carried during the night time walking tours.
The flag commonly associated with CW is the Grand Union Jack. It usually flown outside of buildings to denote what's open.
A very distinct blue and white pottery is used (and sold) throughout the historic area.
I'm sure I can think of other ideas that would work for the historic area.