No, can't paint the rails. You could and see what happens but I wouldn't make that choice.

First thing you have to do is check the color specifications for the door. Most stipulate that you can't repaint the door with a color that's darker than the original. Some will give you a range in terms of LRV, it's usually 55 to 65.

I've seen the same thing on IG. A lot of them have been painted black. No doubt they will be replacing the doors sooner than later.

As far as paint and process, choose your brand and let the pros at the store guide you on product and step by step.