Hex #55606c or rgb(85,96,108) in RGB space is the tint of blue. It has hue angle of 211.30 degrees, value = 42 and saturation = 21. #55606c can be obtained by mixing 4 colors: 5 drops of magenta, 3 drops of cyan, 4 drops of green, 3 drops of black.
Nearest safe hex - #666666. Below you can see the block with #55606c color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #55606c to the mixer and play with it.