Hex #556d87 or rgb(85,109,135) in RGB space is the tint of blue. It has hue angle of 211.20 degrees, value = 53 and saturation = 37. #556d87 can be obtained by mixing 4 colors: 1 drop of yellow, 3 drops of red, 5 drops of blue, 3 drops of cyan.
Nearest safe hex - #666699. Below you can see the block with #556d87 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556d87 to the mixer and play with it.