Hex #155b72 or rgb(21,91,114) in RGB space is the tint of bluish cian. It has hue angle of 194.84 degrees, value = 45 and saturation = 82. #155b72 can be obtained by mixing 4 colors: 1 drop of red, 2 drops of blue, 4 drops of cyan, 5 drops of black.
Nearest safe hex - #006666. Below you can see the block with #155b72 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #155b72 to the mixer and play with it.