What color is Drawing, Study of an Abstract Landscape, n.d. ?

Source Crayola® CSS3 CSS4
#537b8c
 
#4a646c
deep space sparkle
#708090
slate gray
#708090
slategrey
#bbbfa5
 
#cdc5c2
silver
#c0c0c0
silver
#c0c0c0
silver
#62523f
 
#714b23
raw umber
#556b2f
dark olive green
#556b2f
darkolivegreen
#5b6667
 
#4a646c
deep space sparkle
#696969
dim grey
#696969
dimgrey