Hex #128a5b or rgb(18,138,91) in RGB space is the tint of teal. It has hue angle of 156.50 degrees, value = 54 and saturation = 87. #128a5b can be obtained by mixing 4 colors: 4 drops of cyan, 4 drops of green, 1 drop of white, 5 drops of black.
Nearest safe hex - #009966. Below you can see the block with #128a5b color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #128a5b to the mixer and play with it.