Hex #552b2b or rgb(85,43,43) in RGB space is the tint of red. It has hue angle of 0.00 degrees, value = 33 and saturation = 49. #552b2b can be obtained by mixing 3 colors: 1 drop of red, 1 drop of white, 4 drops of black.
Nearest safe hex - #663333. Below you can see the block with #552b2b color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #552b2b to the mixer and play with it.