Hex #66181a or rgb(102,24,26) in RGB space is the tint of red. It has hue angle of 358.46 degrees, value = 40 and saturation = 76. #66181a can be obtained by mixing 3 colors: 4 drops of red, 1 drop of cyan, 5 drops of black.
Nearest safe hex - #660033. Below you can see the block with #66181a color and its structure: in procentage ratio and in drops of pigments. Click "TRY" button to move #66181a to the mixer and play with it.