Hex #667100 or rgb(102,113,0) in RGB space is the tint of yellow. It has hue angle of 65.84 degrees, value = 44 and saturation = 100. #667100 can be obtained by mixing 3 colors: 4 drops of yellow, 1 drop of green, 5 drops of black.
Nearest safe hex - #666600. Below you can see the block with #667100 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #667100 to the mixer and play with it.