Hex #667b7d or rgb(102,123,125) in RGB space is the tint of cyan. It has hue angle of 185.22 degrees, value = 49 and saturation = 18. #667b7d can be obtained by mixing 4 colors: 2 drops of yellow, 5 drops of blue, 4 drops of white, 4 drops of black.
Nearest safe hex - #666666. Below you can see the block with #667b7d color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #667b7d to the mixer and play with it.