I'd be tempted to take off all the shutters, since they're way too small for your wide windows. Second choice black, although the current white isn't bad. Frond door I'd go with a cheery color that contrasts with the brick, especially to come out from under the new roof -- a bright medium blue, say.

Most 'greys' have an undertone and if you choose one with a blue undertone it will perfectly complement your red bricks. Don't think colour, think temperature. If everything is red or brown (which is essentially orange) then some cool will really balance it. This is Indian grey sandstone with red brick.

I suggested blue in your other thread. I like Denita's pick. A clean cool blue without muddy undertones will be an attractive contrast to your red brick. You will have to buy a few samples to see how the colors look in your light.

Regarding door style, I would choose one that mimics the lites/glass in your windows. A few examples... Carriage lights sound nice for the detached garage. A door with windows would also be nice. I like the white. White or black for the front door would work, but white would give it more presence. Paint the downspouts to blend with the brick. Your brick with some white and black is classic and nice, like this...