Hex #66a1a5 or rgb(102,161,165) in RGB space is the tint of cyan. It has hue angle of 183.81 degrees, value = 65 and saturation = 38. #66a1a5 can be obtained by mixing 4 colors: 4 drops of magenta, 5 drops of cyan, 4 drops of green, 2 drops of white.
Nearest safe hex - #669999. Below you can see the block with #66a1a5 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66a1a5 to the mixer and play with it.