Hex #999b88 or rgb(153,155,136) in RGB space is the tint of yellow. It has hue angle of 66.32 degrees, value = 61 and saturation = 12. #999b88 can be obtained by mixing 4 colors: 5 drops of red, 4 drops of cyan, 2 drops of green, 4 drops of white.
Nearest safe hex - #999999. Below you can see the block with #999b88 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #999b88 to the mixer and play with it.