What color is Mailing, New Institute Announcement, 2013 ?

Source Crayola® CSS3 CSS4
#6b8a7f
 
#757575
sonic silver
#708090
slate gray
#708090
slategrey
#4f4d5a
 
#414a4c
outer space
#2f4f4f
dark slate gray
#2f4f4f
darkslategrey
#98a39f
 
#979aaa
manatee
#a9a9a9
dark gray
#a9a9a9
darkgrey
#737181
 
#757575
sonic silver
#808080
grey
#808080
grey