Hex #408039 or rgb(64,128,57) in RGB space is the tint of green. It has hue angle of 114.08 degrees, value = 50 and saturation = 55. #408039 can be obtained by mixing 4 colors: 3 drops of yellow, 4 drops of blue, 3 drops of green, 2 drops of black.
Nearest safe hex - #339933. Below you can see the block with #408039 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #408039 to the mixer and play with it.