Hex #156b1d or rgb(21,107,29) in RGB space is the tint of green. It has hue angle of 125.58 degrees, value = 42 and saturation = 80. #156b1d can be obtained by mixing 4 colors: 1 drop of yellow, 2 drops of blue, 5 drops of green, 4 drops of black.
Nearest safe hex - #006633. Below you can see the block with #156b1d color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #156b1d to the mixer and play with it.