Hex #5591b9 or rgb(85,145,185) in RGB space is the tint of blue. It has hue angle of 204.00 degrees, value = 73 and saturation = 54. #5591b9 can be obtained by mixing 4 colors: 1 drop of red, 2 drops of blue, 2 drops of cyan, 1 drop of white.
Nearest safe hex - #6699cc. Below you can see the block with #5591b9 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #5591b9 to the mixer and play with it.