Hex #558647 or rgb(85,134,71) in RGB space is the tint of grass green. It has hue angle of 106.67 degrees, value = 53 and saturation = 47. #558647 can be obtained by mixing 4 colors: 3 drops of yellow, 1 drop of red, 5 drops of blue, 3 drops of green.
Nearest safe hex - #669933. Below you can see the block with #558647 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #558647 to the mixer and play with it.