Hex #557900 or rgb(85,121,0) in RGB space is the tint of lime. It has hue angle of 77.85 degrees, value = 47 and saturation = 100. #557900 can be obtained by mixing 2 colors: 1 drop of red, 2 drops of green.
Nearest safe hex - #666600. Below you can see the block with #557900 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #557900 to the mixer and play with it.