Hex #558783 or rgb(85,135,131) in RGB space is the tint of cyan. It has hue angle of 175.20 degrees, value = 53 and saturation = 37. #558783 can be obtained by mixing 4 colors: 2 drops of magenta, 5 drops of blue, 5 drops of green, 3 drops of white.
Nearest safe hex - #669999. Below you can see the block with #558783 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #558783 to the mixer and play with it.