Hex #668591 or rgb(102,133,145) in RGB space is the tint of bluish cian. It has hue angle of 196.74 degrees, value = 57 and saturation = 30. #668591 can be obtained by mixing 4 colors: 1 drop of blue, 1 drop of cyan, 4 drops of white, 4 drops of black.
Nearest safe hex - #669999. Below you can see the block with #668591 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #668591 to the mixer and play with it.