Hex #155387 or rgb(21,83,135) in RGB space is the tint of blue. It has hue angle of 207.37 degrees, value = 53 and saturation = 84. #155387 can be obtained by mixing 4 colors: 1 drop of magenta, 4 drops of blue, 3 drops of cyan, 4 drops of black.
Nearest safe hex - #006699. Below you can see the block with #155387 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #155387 to the mixer and play with it.