Hex #556172 or rgb(85,97,114) in RGB space is the tint of blue. It has hue angle of 215.17 degrees, value = 45 and saturation = 25. #556172 can be obtained by mixing 3 colors: 1 drop of blue, 2 drops of white, 3 drops of black.
Nearest safe hex - #666666. Below you can see the block with #556172 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556172 to the mixer and play with it.