Hex #999b5e or rgb(153,155,94) in RGB space is the tint of yellow. It has hue angle of 61.97 degrees, value = 61 and saturation = 39. #999b5e can be obtained by mixing 4 colors: 3 drops of yellow, 1 drop of blue, 3 drops of white, 3 drops of black.
Nearest safe hex - #999966. Below you can see the block with #999b5e color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #999b5e to the mixer and play with it.