For all semi permanent makeup procedures, it is imperative that you complete a 6 week touch up following the initial procedure. During the healing process your brows will fade anywhere from 30-50% of the initial color, however this is not guaranteed as everyone heals differently. At the initial appointment, I believe in being conservative with color and can then darken if necessary at your touch up. 

At the touch up, by adding more pigment in the skin will also result in longer retention of the color.