Side Road, Color
A Side Road symbol sign may be used in advance of an intersection to indicate the presence of an intersection and the possibility of turning or entering traffic. The relative importance of the intersecting roadways may be shown by different widths of lines in the symbol. An advance street name plaque may be installed above or below an Intersection Warning sign.
Federal Highway Administration Manual on Uniform Traffic Control Devices for Streets and Highways, 2003 Edition (including 2004 and 2007 revisions) (Washington, DC: United States Department of Transportation, 2007)