Hex #559dab or rgb(85,157,171) in RGB space is the tint of bluish cian. It has hue angle of 189.77 degrees, value = 67 and saturation = 50. #559dab can be obtained by mixing 4 colors: 1 drop of yellow, 3 drops of blue, 1 drop of cyan, 1 drop of white.
Nearest safe hex - #669999. Below you can see the block with #559dab color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #559dab to the mixer and play with it.