Hex #556b7d or rgb(85,107,125) in RGB space is the tint of blue. It has hue angle of 207.00 degrees, value = 49 and saturation = 32. #556b7d can be obtained by mixing 4 colors: 1 drop of yellow, 5 drops of blue, 4 drops of white, 5 drops of black.
Nearest safe hex - #666666. Below you can see the block with #556b7d color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556b7d to the mixer and play with it.