All permanent makeup, even though called "permanent" fades over time.  It is called "permanent" because it cannot be washed off.  Also, the pigment molecules used in permanent makeup procedures will forever remain in the skin and when they become light in appearance they will reflect an imprint in the skin.

It is common knowledge that all color fades.  So of course, permanent makeup, being color, will fade as well.  Clothing fades, furniture fades, paints fade, etc.  They all have a limited life span.  They do not remain stable forever.  Hair color very frequently requires color refreshers due to many of the same factors that fades permanent makeup.  Some of these factors include exposure to sunlight, chemicals such as those found in skin care products like Retin-A hydroxy acids, glycolic acids, etc.; changing health conditions; effects of various medical treatments, such as chemotherapy/radiation; effects of various medications which alter body chemistry; hormonal changes; chlorine; salt water, etc.  All of those factors, plus basic body metabolism, will erode the permanent makeup color over time and a color refresher will be needed.  

Traditional tattoos/body art fades over time too.  Due to the fact that an appendage (an arm or a leg, for instance) has a sluggish metabolism as compared to the face (where permanent makeup is applied) which has an accelerated metabolism, the vascularized face "eats" or metabolizes the pigment at a much faster rate.  Therefore, a color refresher will be needed on facial permanent makeup much sooner than traditional body art tattoos.  

There is also a difference between the inks which are used in traditional body art and the  pigment used in permanent makeup.  The inks used in body art tattoos will outlast permanent makeup pigments.  The reason that inks cannot be used on the face is because the face will metabolize the inks much differently and the color results will be detrimental.  For instance, if brown ink is used on eyebrows, over time as it is metabolized, the eyebrows may end up resembling peacock blue, purple, canary yellow or bright red.  This is because the primary colors used in traditional tattooing outlive and are very stable, as compared to a soft blonde or brown colors, which are weaker, complex colors.  Therefore, permanent makeup technicians use pigments for their permanent makeup procedures and color refreshers/maintenance procedures are recommended to keep it looking fresh.  

Eyebrow colors are complex colors consisting of combinations of color mixtures.  This means that they are less stable and lack longevity as compared to primary colors (used in traditional tattooing).

Therefore, again, eyebrows will require refreshing, or a color "boost" to keep them looking fresh.  There is no way around this, as eyebrow pigments are "complex" colors.

As the eyebrow starts to degrade, you'll notice that initially they'll become a lighter version of what they once were when first done.  Then, you may also notice that generally the gold tones or warm tones will eventually begin to disappear as they metabolize more quickly than the other colors within the eyebrow pigments.  This is the normal course of color degradation with normal metabolizing of color.  Again, as noted above, if other factors are introduced to the metabolizing of color, such as medication changes, excessive sunshine, etc.,  you will need to have a color refresher sooner.   

A very commonly asked question is, "How long will my permanent makeup last?"  There is no simple answer to this.  We tell our clients, "When you are feeling the need to pick up a pencil to add more color is the time to pick up the phone to schedule your color refresher appointment".