Hex #557156 or rgb(85,113,86) in RGB space is the tint of green. It has hue angle of 122.14 degrees, value = 44 and saturation = 25. #557156 can be obtained by mixing 4 colors: 1 drop of yellow, 3 drops of magenta, 3 drops of blue, 5 drops of green.
Nearest safe hex - #666666. Below you can see the block with #557156 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #557156 to the mixer and play with it.