Hex #3990a1 or rgb(57,144,161) in RGB space is the tint of bluish cian. It has hue angle of 189.81 degrees, value = 63 and saturation = 65. #3990a1 can be obtained by mixing 4 colors: 1 drop of blue, 3 drops of cyan, 2 drops of white, 3 drops of black.
Nearest safe hex - #339999. Below you can see the block with #3990a1 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #3990a1 to the mixer and play with it.