Hex #403f2b or rgb(64,63,43) in RGB space is the tint of yellow. It has hue angle of 57.14 degrees, value = 25 and saturation = 33. #403f2b can be obtained by mixing 4 colors: 1 drop of red, 1 drop of blue, 1 drop of green, 1 drop of black.
Nearest safe hex - #333333. Below you can see the block with #403f2b color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #403f2b to the mixer and play with it.