Hi Trinder
I don't think there would be much of a difference in the technique we use to apply the pigment, the difference is in the pigment we use, by the looks of it Melina uses a semi permanent pigment that fades away after 2 years.
We use a more permanent pigment, it will still soften over the years, but our treatment will last 3 to 6 years before needing a touch up, the reason for this is that we do not penetrate into the skin as deep as a regular tattoo and we don't use regular tattoo ink that is designed to last a lifetime.
The pigment will not bleed as we only penetrate 2 layers deep, which holds the pigment in the collagen matrix of the dermis which will not allow the pigment to spread as opposed to a normal tattoo which is deeper and will blur and spread over the years.
The pigment we use will only soften into a lighter colour of the original colour that was deposited into the scalp, which does not contain any other colours, so it will not turn blue or green.
So even if your hair turns grey or white later on it will still blend with the pigment as you can stop getting it touched up and let it soften into a lighter colour,
Hope this helps
Thanks
Jason