Hex #155a4e or rgb(21,90,78) in RGB space is the tint of greenish cian. It has hue angle of 169.57 degrees, value = 35 and saturation = 77. #155a4e can be obtained by mixing 4 colors: 4 drops of blue, 3 drops of green, 1 drop of white, 4 drops of black.
Nearest safe hex - #006666. Below you can see the block with #155a4e color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #155a4e to the mixer and play with it.