Why Submarines are Marked Black in Colour All Over the World Military Submarines Are Marked as Black or Grey in Colour. Read our blog to know Why Submarines are Marked Black in Colour. They are marked Black or Grey Because:- Black Colour Absorbs Light thus it is impossible for Enemy Ships to See Submarines With Naked Eyes Thus Submarines are easily not visible to the Enemies Submarines Marked as Black or Grey Gives Camouflage Effect thus Enemies Can’t Identify the Submarines Submarines used other than Military Purposes are marked green or blue and are basically used for Deep Sea Exploration