Hex #556799 or rgb(85,103,153) in RGB space is the tint of blue violet. It has hue angle of 224.12 degrees, value = 60 and saturation = 44. #556799 can be obtained by mixing 4 colors: 4 drops of red, 1 drop of magenta, 5 drops of blue, 5 drops of cyan.
Nearest safe hex - #666699. Below you can see the block with #556799 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #556799 to the mixer and play with it.