If you could post a better picture showing the entire house and the brick you're talking about it would be easier to answer your questions.

Depending on the shade of brick you have, gray will work! I also love sage green with most bricks. It also depends on the color of your roof.

The brick is on the bottom of the house, the porch, and around the front garden area. Here is another photo, hopefully it is more helpful.

My house has variegated red brick. The house is painted medium gray with cream colored trim. I was told that the additional pigment in the cream color would make the paint last longer, but white would look fine as well. The front door is natural wood, colorwise leaning toward a medium dark maple finish. Personally, I would not paint brick.