Hex #554f00 or rgb(85,79,0) in RGB space is the tint of yellow. It has hue angle of 55.76 degrees, value = 33 and saturation = 100. #554f00 can be obtained by mixing 2 colors: 1 drop of yellow, 2 drops of black.
Nearest safe hex - #666600. Below you can see the block with #554f00 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #554f00 to the mixer and play with it.