All the above makes perfect sense. Since the subject has come up, though, maybe it's worth talking a little about the general effect of age on paint. I learned some interesting stuff about that, albeit in an extremely informal, un-scientific way, when I was working as a curator in a maritime museum some years back.
Modern paints are wonderful, sophisticated things, but any paint is going to change color at least a little bit as it gets older. The worst enemy of a painted finish (or virtually any other form of coloration) is light, and the most damaging form of light is sunlight. I can get out of my depth in a hurry here, but I do know that sunlight contains a high concentration of rays at the ultra-violet end of the spectrum, and ultra-violet light is devastating to paints, inks, and dyes. Red seems to be especially susceptible.
I once had two identical copies of a paperback book, printed on glossy paper, in my office. One item on the cover was an American flag. I left one copy on a shelf in the shade, and accidentally left the other one on my desk, where the sun hit it for several hours each day. Over a period of three or four months the red on the flag that was in the sun disappeared completely; it looked like the flag had been printed in grey.
Quite a few years ago I paid a visit to the British Army Museum, in London. Red-dyed fabric is pretty important to that institution. Visitors were warned before they entered that the light levels were kept extremely low, in order to preserve the uniforms, battle flags, etc. It was so dark in the galleries that I was afraid of falling over something - though of course my eyes eventually got used to it. That was quite a long time ago; I don't know whether that particular museum may have come up with a better solution to the problem since then.
If you want your models to last, keep them out of the sun. If there's no way to avoid letting sunlight fall on them, look into the possibility of putting UV-proof film on the windows. This stuff used to be available only to the museum and preservation trade, but recently places like Lowe's and Home Depot have started selling it. (It also cuts down on heat, lowering your air conditioning bill - and raising your heating bill in the winter.)
The second-worst light source is flourescent light, which also has a pretty high UV content. It's nowhere near as dangerous to models as sunlight is, but it makes sense to avoid it if possible. You can buy UV-blocking plastic tubes that slip over flourescent tubes; if you have a big, valuable model collection that has to be kept in that kind of light, those tubes might be a reasonable investment. (They don't cost much.) Nowadays dealers sell quite a variety of flourescent tubes that give off dramatically different kinds of light for different applications; if you want your models to look their best to the human eye, it's worth taking a look at what's available.
To my eye, most models look their best under plain, old-fashioned incandescent light. The good old light bulb casts a warm, friendly light that, though the harsh shadows it casts can sometimes be distracting, shows off the detail and color of the typical model at its most attractive. When I was at the museum I discovered that old ship models, like old people (such as myself) tend to look better when the light isn't too bright and harsh.
Hope a little of that is of at least a little interest. Lighting can make a surprising difference in how a model looks - and on how long it lasts.