Hex #557f97 or rgb(85,127,151) in RGB space is the tint of bluish cian. It has hue angle of 201.82 degrees, value = 59 and saturation = 44. #557f97 can be obtained by mixing 4 colors: 2 drops of blue, 1 drop of cyan, 3 drops of white, 3 drops of black.
Nearest safe hex - #666699. Below you can see the block with #557f97 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #557f97 to the mixer and play with it.