Hex #558b95 or rgb(85,139,149) in RGB space is the tint of bluish cian. It has hue angle of 189.38 degrees, value = 58 and saturation = 43. #558b95 can be obtained by mixing 4 colors: 1 drop of magenta, 5 drops of blue, 3 drops of green, 3 drops of white.
Nearest safe hex - #669999. Below you can see the block with #558b95 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #558b95 to the mixer and play with it.