Hex #556d42 or rgb(85,109,66) in RGB space is the tint of olive. It has hue angle of 93.49 degrees, value = 43 and saturation = 39. #556d42 can be obtained by mixing 4 colors: 2 drops of magenta, 4 drops of green, 1 drop of white, 2 drops of black.
Nearest safe hex - #666633. Below you can see the block with #556d42 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556d42 to the mixer and play with it.