What color is Blueprint, Apartment House on Rue Heine, Coude dans L'Axe de la Facade, ca. 1925 ?

Source Crayola® CSS3 CSS4
#567d97
 
#757575
sonic silver
#708090
slate gray
#708090
slategrey
#87a2af
 
#979aaa
manatee
#a9a9a9
dark gray
#a9a9a9
darkgrey