Hex #558ca1 or rgb(85,140,161) in RGB space is the tint of bluish cian. It has hue angle of 196.58 degrees, value = 63 and saturation = 47. #558ca1 can be obtained by mixing 3 colors: 3 drops of red, 1 drop of blue, 5 drops of cyan.
Nearest safe hex - #669999. Below you can see the block with #558ca1 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #558ca1 to the mixer and play with it.