(in the US) White with black letter/numerals.
Symantics being what they are.....I would say yes. They are on the driver's test as regulatory signs, and, they are supposed to "regulate speed".Added: A rectangular/square sign consisting of black...
Speed limit sign
yes
enforces the lawAdded; An example would be a speed limit sign. That sign regulates the speed at which you may lawfully drive.
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