Hex #557d42 or rgb(85,125,66) in RGB space is the tint of grass green. It has hue angle of 100.68 degrees, value = 49 and saturation = 47. #557d42 can be obtained by mixing 4 colors: 2 drops of red, 2 drops of blue, 4 drops of green, 1 drop of white.
Nearest safe hex - #666633. Below you can see the block with #557d42 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #557d42 to the mixer and play with it.