Hex #551b56 or rgb(85,27,86) in RGB space is the tint of magenta. It has hue angle of 298.98 degrees, value = 34 and saturation = 69. #551b56 can be obtained by mixing 4 colors: 4 drops of magenta, 2 drops of blue, 1 drop of green, 5 drops of black.
Nearest safe hex - #663366. Below you can see the block with #551b56 color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #551b56 to the mixer and play with it.