Hex #557240 or rgb(85,114,64) in RGB space is the tint of olive. It has hue angle of 94.80 degrees, value = 45 and saturation = 44. #557240 can be obtained by mixing 4 colors: 3 drops of red, 3 drops of blue, 5 drops of green, 1 drop of white.
Nearest safe hex - #666633. Below you can see the block with #557240 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #557240 to the mixer and play with it.