Hex #557c40 or rgb(85,124,64) in RGB space is the tint of grass green. It has hue angle of 99.00 degrees, value = 49 and saturation = 48. #557c40 can be obtained by mixing 4 colors: 1 drop of red, 4 drops of green, 3 drops of white, 4 drops of black.
Nearest safe hex - #666633. Below you can see the block with #557c40 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #557c40 to the mixer and play with it.