Hex #556656 or rgb(85,102,86) in RGB space is the tint of green. It has hue angle of 123.53 degrees, value = 40 and saturation = 17. #556656 can be obtained by mixing 3 colors: 2 drops of magenta, 1 drop of blue, 3 drops of green.
Nearest safe hex - #666666. Below you can see the block with #556656 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556656 to the mixer and play with it.