Hex #66ccdd or rgb(102,204,221) in RGB space is the tint of bluish cian. It has hue angle of 188.57 degrees, value = 87 and saturation = 54. #66ccdd can be obtained by mixing 4 colors: 1 drop of blue, 4 drops of cyan, 4 drops of white, 1 drop of black.
Nearest safe hex - #66cccc. Below you can see the block with #66ccdd color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66ccdd to the mixer and play with it.