Hex #668588 or rgb(102,133,136) in RGB space is the tint of cyan. It has hue angle of 185.29 degrees, value = 53 and saturation = 25. #668588 can be obtained by mixing 4 colors: 1 drop of yellow, 3 drops of red, 2 drops of blue, 4 drops of cyan.
Nearest safe hex - #669999. Below you can see the block with #668588 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #668588 to the mixer and play with it.