Local Color
Global Hint (12:15): All of the seven locations are very close to a specific, very special, kind of street marking, which could be described as a kind of Local Color.
33°46'53.3"N, 84°23'08.9"W33°59'25.8"N, 118°28'06.0"W
37°51'06.6"N, 122°15'50.9"W
41°58'07.3"N, 91°39'25.4"W
40°44'23.3"N, 74°01'48.8"W
45°49'36.6"N, 77°06'34.6"W
33°54'53.3"S, 18°25'15.2"E