Hex #557639 or rgb(85,118,57) in RGB space is the tint of olive. It has hue angle of 92.46 degrees, value = 46 and saturation = 52. #557639 can be obtained by mixing 4 colors: 4 drops of yellow, 4 drops of blue, 1 drop of green, 3 drops of black.
Nearest safe hex - #666633. Below you can see the block with #557639 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #557639 to the mixer and play with it.