Hex #667d80 or rgb(102,125,128) in RGB space is the tint of cyan. It has hue angle of 186.92 degrees, value = 50 and saturation = 20. #667d80 can be obtained by mixing 4 colors: 1 drop of red, 3 drops of magenta, 3 drops of cyan, 3 drops of green.
Nearest safe hex - #666699. Below you can see the block with #667d80 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #667d80 to the mixer and play with it.