Hex #557577 or rgb(85,117,119) in RGB space is the tint of cyan. It has hue angle of 183.53 degrees, value = 47 and saturation = 29. #557577 can be obtained by mixing 4 colors: 5 drops of red, 3 drops of blue, 5 drops of cyan, 2 drops of green.
Nearest safe hex - #666666. Below you can see the block with #557577 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #557577 to the mixer and play with it.