Hex #666d8e or rgb(102,109,142) in RGB space is the tint of blue violet. It has hue angle of 229.50 degrees, value = 56 and saturation = 28. #666d8e can be obtained by mixing 4 colors: 1 drop of red, 5 drops of blue, 5 drops of white, 4 drops of black.
Nearest safe hex - #666699. Below you can see the block with #666d8e color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #666d8e to the mixer and play with it.