Hex #667800 or rgb(102,120,0) in RGB space is the tint of lime. It has hue angle of 69.00 degrees, value = 47 and saturation = 100. #667800 can be obtained by mixing 4 colors: 1 drop of yellow, 1 drop of red, 2 drops of green, 1 drop of black.
Nearest safe hex - #666600. Below you can see the block with #667800 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #667800 to the mixer and play with it.