Just have them painted, the value will increase and the color of the vinyl and paint around it won't fade and cause other problems down the road.
Disagree. Use vinyl first.
1. You may not end up liking the color in which case it's an easy fix. Plus, when it comes time to sell the car your buyer may especialy not like the color you picked. If it is not a factory offered color combination it may detract from the value as well. You may want to change the color yourself in a year or two.
2. A quality vinyl installation is almost indistinguishable for paint, you need to be six inched away to tell the difference, if that. Note I said QUALITY installation by a pro, not by your neighbor Biff. Also, modern vinyl is guarenteed not to fade or crack for 5-7 years, and that is OUTDOOR exposure not garage queens. The way most of us care for our cars it will last indefinitely. And the surrounding paint won't fade unless you keep your car out in the hot sun every day for years.
3. You can always paint them on later. A vinyl installation may cost you $300-500, and a good paint job 10 times that. And it ain't coming off. Be sure you want it.