Hex #664f9a or rgb(102,79,154) in RGB space is the tint of purple violet. It has hue angle of 258.40 degrees, value = 60 and saturation = 49. #664f9a can be obtained by mixing 4 colors: 1 drop of magenta, 2 drops of blue, 1 drop of white, 1 drop of black.
Nearest safe hex - #666699. Below you can see the block with #664f9a color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #664f9a to the mixer and play with it.