Hex #178e93 or rgb(23,142,147) in RGB space is the tint of cyan. It has hue angle of 182.42 degrees, value = 58 and saturation = 84. #178e93 can be obtained by mixing 4 colors: 1 drop of yellow, 2 drops of blue, 5 drops of cyan, 3 drops of black.
Nearest safe hex - #009999. Below you can see the block with #178e93 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #178e93 to the mixer and play with it.