Hi!
Here is an area I suppose you didn't expect me to comment in! Surprise! Eugene's cars got me to checking some old boxes of carefully packed models from the seventies. Specifically, those painted with airbrushed Testors Square Bottle Enamels! Here is a neat little note.
Using a Polish for Plastics-Not paint! I was able to restore that incrdible Gloss those paints have! Yup, it's a mild polish for headlight covers from McGuires! try it you'll like it. BUT, be gentle.You don't have to rub hard for results!
This got me curious. I checked on a Airfix old style E Boot I got in the Seventies and painted in Humbrol enamels. It now, instead of a nice Medium Light Grey is now a very nice aged Light Grey green! You can see the greenish tinge under an Ott-Light. I do believe even in the dark, these paints will change because of Temperature and Humidity!