Hex #999c5b or rgb(153,156,91) in RGB space is the tint of yellow. It has hue angle of 62.77 degrees, value = 61 and saturation = 42. #999c5b can be obtained by mixing 4 colors: 5 drops of yellow, 2 drops of blue, 4 drops of white, 4 drops of black.
Nearest safe hex - #999966. Below you can see the block with #999c5b color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #999c5b to the mixer and play with it.