Hex #556a6c or rgb(85,106,108) in RGB space is the tint of cyan. It has hue angle of 185.22 degrees, value = 42 and saturation = 21. #556a6c can be obtained by mixing 4 colors: 2 drops of yellow, 5 drops of blue, 3 drops of white, 5 drops of black.
Nearest safe hex - #666666. Below you can see the block with #556a6c color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556a6c to the mixer and play with it.