Hex #555d72 or rgb(85,93,114) in RGB space is the tint of blue violet. It has hue angle of 223.45 degrees, value = 45 and saturation = 25. #555d72 can be obtained by mixing 4 colors: 3 drops of magenta, 2 drops of cyan, 2 drops of green, 2 drops of black.
Nearest safe hex - #666666. Below you can see the block with #555d72 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #555d72 to the mixer and play with it.