Hex #556400 or rgb(85,100,0) in RGB space is the tint of lime. It has hue angle of 69.00 degrees, value = 39 and saturation = 100. #556400 can be obtained by mixing 4 colors: 1 drop of yellow, 1 drop of red, 2 drops of green, 2 drops of black.
Nearest safe hex - #666600. Below you can see the block with #556400 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556400 to the mixer and play with it.