Hex #155987 or rgb(21,89,135) in RGB space is the tint of blue. It has hue angle of 204.21 degrees, value = 53 and saturation = 84. #155987 can be obtained by mixing 4 colors: 1 drop of red, 5 drops of blue, 3 drops of cyan, 3 drops of black.
Nearest safe hex - #006699. Below you can see the block with #155987 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #155987 to the mixer and play with it.