Hex #664f8e or rgb(102,79,142) in RGB space is the tint of purple violet. It has hue angle of 261.90 degrees, value = 56 and saturation = 44. #664f8e can be obtained by mixing 4 colors: 1 drop of red, 5 drops of magenta, 5 drops of cyan, 4 drops of black.
Nearest safe hex - #666699. Below you can see the block with #664f8e color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #664f8e to the mixer and play with it.