Hex #156979 or rgb(21,105,121) in RGB space is the tint of bluish cian. It has hue angle of 189.60 degrees, value = 47 and saturation = 83. #156979 can be obtained by mixing 4 colors: 1 drop of red, 1 drop of blue, 5 drops of cyan, 5 drops of black.
Nearest safe hex - #006666. Below you can see the block with #156979 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #156979 to the mixer and play with it.