What color is Unknown ?

Source Crayola® CSS3 CSS4
#42403d
 
#414a4c
outer space
#2f4f4f
dark slate gray
#2f4f4f
darkslategrey
#858b90
 
#95918c
gray
#778899
light slate grey
#778899
lightslategrey
#2e201c
 
#000000
black
#000000
black
#000000
black