Hex #66adb3 or rgb(102,173,179) in RGB space is the tint of cyan. It has hue angle of 184.68 degrees, value = 70 and saturation = 43. #66adb3 can be obtained by mixing 3 colors: 3 drops of cyan, 4 drops of white, 3 drops of black.
Nearest safe hex - #6699cc. Below you can see the block with #66adb3 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66adb3 to the mixer and play with it.