Hex #663f5b or rgb(102,63,91) in RGB space is the tint of crimson. It has hue angle of 316.92 degrees, value = 40 and saturation = 38. #663f5b can be obtained by mixing 4 colors: 4 drops of red, 2 drops of magenta, 4 drops of cyan, 5 drops of black.
Nearest safe hex - #663366. Below you can see the block with #663f5b color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #663f5b to the mixer and play with it.