What color is Drawing, Valley of the Arno ?

Source Crayola® CSS3 CSS4
#61777d
 
#757575
sonic silver
#696969
dim grey
#696969
dimgrey
#748f7d
 
#757575
sonic silver
#808080
grey
#808080
grey
#62779a
 
#757575
sonic silver
#708090
slate gray
#708090
slategrey
#40565c
 
#414a4c
outer space
#2f4f4f
dark slate gray
#2f4f4f
darkslategrey