Hex #559839 or rgb(85,152,57) in RGB space is the tint of grass green. It has hue angle of 102.32 degrees, value = 60 and saturation = 63. #559839 can be obtained by mixing 4 colors: 3 drops of yellow, 2 drops of cyan, 1 drop of green, 3 drops of black.
Nearest safe hex - #669933. Below you can see the block with #559839 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #559839 to the mixer and play with it.