Hex #66acdd or rgb(102,172,221) in RGB space is the tint of blue. It has hue angle of 204.71 degrees, value = 87 and saturation = 54. #66acdd can be obtained by mixing 4 colors: 1 drop of magenta, 5 drops of blue, 4 drops of cyan, 5 drops of white.
Nearest safe hex - #6699cc. Below you can see the block with #66acdd color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66acdd to the mixer and play with it.