Hex #555b1d or rgb(85,91,29) in RGB space is the tint of yellow. It has hue angle of 65.81 degrees, value = 36 and saturation = 68. #555b1d can be obtained by mixing 3 colors: 2 drops of yellow, 1 drop of blue, 3 drops of black.
Nearest safe hex - #666633. Below you can see the block with #555b1d color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #555b1d to the mixer and play with it.