I do plan on painting the project after I finish. I want something that will last a several years outside and I know I will more than likely have to cure resin.

Whats "pretty easily" ?
Do you have structural load expectations?
Do cosmetics matter?

No load. No pressure. The fiber will have to be able set in a few very detailed shapes but nothing at 90 degrees(more curves). The color does not matter as I plan to paint, but the darker the better. The item is more cosmetic.

500°F = 260°C...you want paint of some sort to stay on at this temperature? Does it need handling when hot at all? A high temperature paint and good adhesion to a substrate like epoxy or BMI might be advisable. A polymer-based paint like polypropylene, polyester or epoxy won't do; there are presumably higher temp polymer-based paints, but I'm not familiar with any.

Glass would be an obvious cheap fiber but tends not to make a dark composite. Are you sure you want a fiber? With nominal handling load or no load, just some sort of unreinforced plastic might be sensible. Some of the high temperature epoxy that Master Bond are always trying to sell me might do. Does it have any self weight applied at 500°F?

Not quite sure what you mean by "...I will more than likely have to cure resin." Are you curing stuff in it/on it at that temp? Or is that just knowing it'll be a high temp cure?

Adding dye or graphite powder filler to the matrix might be an easy way to darken it a bit with glass fibers. That would need a suitable resin. Of course, carbon fiber (or maybe basalt fiber if you can get any) makes a pretty black composite.

Can't help wondering what the heck this is...it's an ornament that's going to sit in a garden being rained on for 20 years and occasionally be greased up and exposed to 500°F? Weird!