Hex #556439 or rgb(85,100,57) in RGB space is the tint of lime. It has hue angle of 80.93 degrees, value = 39 and saturation = 43. #556439 can be obtained by mixing 4 colors: 1 drop of yellow, 4 drops of red, 5 drops of blue, 5 drops of green.
Nearest safe hex - #666633. Below you can see the block with #556439 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556439 to the mixer and play with it.