Hex #669ac4 or rgb(102,154,196) in RGB space is the tint of blue. It has hue angle of 206.81 degrees, value = 77 and saturation = 48. #669ac4 can be obtained by mixing 4 colors: 4 drops of blue, 1 drop of cyan, 4 drops of white, 1 drop of black.
Nearest safe hex - #6699cc. Below you can see the block with #669ac4 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #669ac4 to the mixer and play with it.