Hex #556066 or rgb(85,96,102) in RGB space is the tint of bluish cian. It has hue angle of 201.18 degrees, value = 40 and saturation = 17. #556066 can be obtained by mixing 4 colors: 4 drops of red, 5 drops of cyan, 1 drop of white, 5 drops of black.
Nearest safe hex - #666666. Below you can see the block with #556066 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556066 to the mixer and play with it.