Hex #15679c or rgb(21,103,156) in RGB space is the tint of blue. It has hue angle of 203.56 degrees, value = 61 and saturation = 87. #15679c can be obtained by mixing 4 colors: 1 drop of magenta, 4 drops of blue, 4 drops of cyan, 3 drops of black.
Nearest safe hex - #006699. Below you can see the block with #15679c color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #15679c to the mixer and play with it.