Hex #666456 or rgb(102,100,86) in RGB space is the tint of yellow. It has hue angle of 52.50 degrees, value = 40 and saturation = 16. #666456 can be obtained by mixing 4 colors: 3 drops of yellow, 1 drop of magenta, 4 drops of blue, 2 drops of black.
Nearest safe hex - #666666. Below you can see the block with #666456 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #666456 to the mixer and play with it.