The color scheme of the train cars and train station match that of the interiors of nearly every room in Mayberry: light green and tan.
Millie will be the last of Howard's serious girlfriend prospects in the series. She was preceded by Irene Fairchild, the county nurse; Alice Harper, Andy's old girlfriend; and Betty Parker, Tommy's sister in the episode "Big Brother." After Millie, Howard will have trouble finding a date for his bachelor pad housewarming.