Hex #156d63 or rgb(21,109,99) in RGB space is the tint of cyan. It has hue angle of 173.18 degrees, value = 43 and saturation = 81. #156d63 can be obtained by mixing 4 colors: 1 drop of magenta, 4 drops of cyan, 2 drops of green, 5 drops of black.
Nearest safe hex - #006666. Below you can see the block with #156d63 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #156d63 to the mixer and play with it.