well any color you want really, but usually i find that eaithre white or the color of your shutters works
white.
you should paint them blue
The plate inside your door which has your VIN number on it, should list your color code as well. You can get that paint either from the dealer, or your could try Google'ing it, and see what you find.
You would first paint a solid color that is the back ground of the wood you want to imitate. Use a good exterior paint. Then, add the grain with a different color(s).
paint it pink
You don't have to. the trim can be a contrasting color. It's your house, if you like it, it's nobody's business.
1) take a paintbrush. 2)dip it in the prefered color of paint. 3)unleash the power of the brush on that door until its... not silver
Red
Brown
If you just want to paint the car the same color or adding a new bumper and want to match the paint, look in your door jam, there is a sticker there with the paint code.
Paint your car what best describes your personality
Getting door with your desired color is the best option. If you already has your plastic door and want to paint, one way is to use spray color as ordinary paint won't do good work.