Hex #66a9cc or rgb(102,169,204) in RGB space is the tint of bluish cian. It has hue angle of 200.59 degrees, value = 80 and saturation = 50. #66a9cc can be obtained by mixing 4 colors: 1 drop of red, 3 drops of blue, 3 drops of cyan, 3 drops of white.
Nearest safe hex - #6699cc. Below you can see the block with #66a9cc color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66a9cc to the mixer and play with it.