I got the ceramic coat from the dealer when I bought my Triton as it was red, and I did not know this at the time but if you see any red tritons that are a few years old getting around they are all pink, unless someone has given it a cut and polish.
The spiel from the salesman was that the paint protection had a guaranteed 12-year protection from fading. I was very dubious of these claims, but as I had it in writing, and I knew red cars are more prone to fading, I paid the extra for the coating.
Well blow me down, less than 12 months later I had a pink Triton! Took it back to the dealer and they got the paint protection guy in, and he blamed the paint. What it was is, that Tritons simply don't have a clear coat, so like all cars used to do, they fade. The paint protection does stuff all and they wouldn't back it up. Fortunately, the car dealership was great and stuck to their word that they would fix it one way or the other. Ended up getting a full respray (with a clear coat this time) at a cost to the dealer of $9K and it stayed shiny and red for the next 10 years I owned it.
I don't think that ceramic coating/paint protection is worth what you pay for it. You may as well just wax it yourself once a year, as even though they claim it lasts for years, it doesn't.
So, there are reasons for that...
Some reds are very prone to fade because they are based on organic pigments, which break down with UV exposure
Inorganic reds (ie oxides) don't break down with UV, but have a more limited colour range (can't be as bright. Same for other brights like yellows and greens)
The "ceramic" coatings aren't really ceramics, but sort of are ..
Often based on stuff like TEOS (tetraethyl orthosilicate), it's more like a molecule that is organic on one side (that does chemically bond to the paint surface, which is why needs good prep, and lasts a long time), and the outward facing side is sort of silicate/silica (which is why they call it ceramic, but it's not).
None of that coating significantly absorbs or reflects UV, so doesn't change organic pigment/dye fade at all, and they shouldn't have promised it would.
Topcoats don't really need clearcoats these days if the pigments are all inorganic, and the paint has a decent UV stabiliser (like HALS)..
And shit reds will still be shit and fade under a clearcoar under the clear has sufficient UV absorber added..
/Paintnerd