Hex #5b9c8c or rgb(91,156,140) in RGB space is the tint of greenish cian. It has hue angle of 165.23 degrees, value = 61 and saturation = 42. #5b9c8c can be obtained by mixing 4 colors: 3 drops of yellow, 2 drops of red, 4 drops of blue, 5 drops of cyan.
Nearest safe hex - #669999. Below you can see the block with #5b9c8c color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #5b9c8c to the mixer and play with it.