Hex #669db3 or rgb(102,157,179) in RGB space is the tint of bluish cian. It has hue angle of 197.14 degrees, value = 70 and saturation = 43. #669db3 can be obtained by mixing 4 colors: 3 drops of magenta, 4 drops of cyan, 2 drops of green, 1 drop of white.
Nearest safe hex - #6699cc. Below you can see the block with #669db3 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #669db3 to the mixer and play with it.