Hex #556240 or rgb(85,98,64) in RGB space is the tint of olive. It has hue angle of 82.94 degrees, value = 38 and saturation = 35. #556240 can be obtained by mixing 4 colors: 4 drops of red, 3 drops of blue, 1 drop of cyan, 4 drops of green.
Nearest safe hex - #666633. Below you can see the block with #556240 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556240 to the mixer and play with it.