Hex #399dda or rgb(57,157,218) in RGB space is the tint of blue. It has hue angle of 202.73 degrees, value = 85 and saturation = 74. #399dda can be obtained by mixing 4 colors: 1 drop of magenta, 3 drops of blue, 4 drops of cyan, 1 drop of white.
Nearest safe hex - #3399cc. Below you can see the block with #399dda color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #399dda to the mixer and play with it.