Hex #667780 or rgb(102,119,128) in RGB space is the tint of bluish cian. It has hue angle of 200.77 degrees, value = 50 and saturation = 20. #667780 can be obtained by mixing 3 colors: 4 drops of red, 5 drops of cyan, 1 drop of black.
Nearest safe hex - #666699. Below you can see the block with #667780 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #667780 to the mixer and play with it.