Hex #557540 or rgb(85,117,64) in RGB space is the tint of olive. It has hue angle of 96.23 degrees, value = 46 and saturation = 45. #557540 can be obtained by mixing 4 colors: 4 drops of yellow, 3 drops of blue, 1 drop of cyan, 4 drops of black.
Nearest safe hex - #666633. Below you can see the block with #557540 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #557540 to the mixer and play with it.