I know I have read about this in this forum, somebody talked about some kind of “ingredient” you need to add to the white paint before apllying it to prevent yellowing, this guy posted this after other user showed his custom arcade stick yellowed on the sides, it was a Custom Taito Vewlix Panel.
I would like to add that “X” chemical before start painting 3 Astro City Panels and prevent them from yellowing.
Go Google RetroBright. That removes Yellowing from aging ABS plastics. And its classified as a DIY cleaner not a paint.
As for the paint it self? I was not aware that paint could yellow from UV rays.
Yes it does, all oil based paints get yellowed over time, you can delay the proccess by applying some urethane varnish over it, or using latex paints instead, but there’s other way to prevent yellowing and I know it was mentioned by another member on this forum but I can’t remember his nickname.