Hex #178c84 or rgb(23,140,132) in RGB space is the tint of cyan. It has hue angle of 175.90 degrees, value = 55 and saturation = 84. #178c84 can be obtained by mixing 4 colors: 1 drop of red, 4 drops of blue, 3 drops of cyan, 3 drops of green.
Nearest safe hex - #009999. Below you can see the block with #178c84 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #178c84 to the mixer and play with it.