Hex #999777 or rgb(153,151,119) in RGB space is the tint of yellow. It has hue angle of 56.47 degrees, value = 60 and saturation = 22. #999777 can be obtained by mixing 4 colors: 3 drops of yellow, 1 drop of red, 4 drops of blue, 2 drops of white.
Nearest safe hex - #999966. Below you can see the block with #999777 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #999777 to the mixer and play with it.