Hex #556b39 or rgb(85,107,57) in RGB space is the tint of olive. It has hue angle of 86.40 degrees, value = 42 and saturation = 47. #556b39 can be obtained by mixing 4 colors: 2 drops of yellow, 1 drop of cyan, 1 drop of white, 5 drops of black.
Nearest safe hex - #666633. Below you can see the block with #556b39 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556b39 to the mixer and play with it.