I would go with a darker brownish-gray, something along the lines of the grout of your fireplace.

Same color as the house so the deck is an extention of it.

Usually, you would want a contrast with the house, but since the deck is directly above the reddish patio, that gives you your contrast.

If you lean blue with a gray stain the orange pavers will look even more orange. So I am thinking of a reddish brown that is closer to the brick color than your siding color.

I would do a lighter red/brown closer to paver color. I'm in Virginia so the lighter the better. I think that it would look better with your brick too.