Hex #664c67 or rgb(102,76,103) in RGB space is the tint of magenta. It has hue angle of 297.78 degrees, value = 40 and saturation = 26. #664c67 can be obtained by mixing 4 colors: 1 drop of red, 3 drops of magenta, 3 drops of blue, 3 drops of green.
Nearest safe hex - #663366. Below you can see the block with #664c67 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #664c67 to the mixer and play with it.