Hex #154b4e or rgb(21,75,78) in RGB space is the tint of cyan. It has hue angle of 183.16 degrees, value = 31 and saturation = 73. #154b4e can be obtained by mixing 4 colors: 4 drops of blue, 2 drops of green, 1 drop of white, 5 drops of black.
Nearest safe hex - #003366. Below you can see the block with #154b4e color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #154b4e to the mixer and play with it.