Hex #809000 or rgb(128,144,0) in RGB space is the tint of yellow. It has hue angle of 66.67 degrees, value = 56 and saturation = 100. #809000 can be obtained by mixing 4 colors: 3 drops of yellow, 2 drops of red, 4 drops of green, 1 drop of black.
Nearest safe hex - #999900. Below you can see the block with #809000 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #809000 to the mixer and play with it.