Depends on your sense of color and aesthetic preferences. Black would certainly work. For a more colorful and contrasting approach, a warm orange would be appealing and analogous to your stained wood siding which tends to be orangey. Other harmonious analogous colors would be a warm yellow-green, a warm yellow or a red-orange.

A complementary color approach to your orangey wood siding would be a blue or blue-green (turquoise, teal, etc).

Not sure that a dark, neutralized blue such as a navy blue or indigo would be a good direction. Black would be better than these, IMO.

Good luck!