What color is Poster, Put On Your Thinking Cap ?

Source Crayola® CSS3 CSS4
#6d767f
 
#757575
sonic silver
#708090
slate gray
#708090
slategrey
#3d4348
 
#414a4c
outer space
#2f4f4f
dark slate gray
#2f4f4f
darkslategrey
#3f5e6e
 
#4a646c
deep space sparkle
#2f4f4f
dark slate gray
#2f4f4f
darkslategrey