Hex #129b6d or rgb(18,155,109) in RGB space is the tint of greenish cian. It has hue angle of 159.85 degrees, value = 61 and saturation = 88. #129b6d can be obtained by mixing 4 colors: 5 drops of cyan, 4 drops of green, 1 drop of white, 4 drops of black.
Nearest safe hex - #009966. Below you can see the block with #129b6d color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #129b6d to the mixer and play with it.