Hex #5591b4 or rgb(85,145,180) in RGB space is the tint of bluish cian. It has hue angle of 202.11 degrees, value = 71 and saturation = 53. #5591b4 can be obtained by mixing 3 colors: 5 drops of blue, 1 drop of green, 3 drops of white.
Nearest safe hex - #6699cc. Below you can see the block with #5591b4 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #5591b4 to the mixer and play with it.