What a fantastic architecture. When you do the brick, if you stain it with masonry /concrete stain you won't have the same issues of maintenance as with paint. They will spray it evenly - through you will have to select a deeper color - either taupe (brown-gray) or a straight charcoal. Love your windows and the classic angled railing. I think a dark gray on the siding will make the orange brick jump even more. What bothers me is the white (railing, fascia, eaves) juxtaposed with the earth toned stuff. So I would recommend camel tones - for the siding - something like http://www.sherwin-williams.com/homeowners/color/find-and-explore-colors/paint-colors-by-family/SW6108-latte/ and the hopsack next darker tone for the garage door. Use the lighter tan for trim that is now white - http://www.sherwin-williams.com/homeowners/color/find-and-explore-colors/paint-colors-by-family/SW6107-nomadic-desert/ Use the darkest tone if you are painting concrete steps. If you think you will stain your brick charcoal, then the white eaves and trim are probably right, and you may not want to paint it tan now and then go back. If your brick were charcoal, then I would block out the rest in grays and blue grays - leave the white eaves, but take the railing and posts charcoal too. A blue gray door - like sw smoky blue.

I would try the Woodcliff Lake, it has a warmer tone than the lighter greys.

I like @kelly's idea of picking a lovely fresh color of paint for the door. You can then bring it down onto the stair risers. Either a solid color to match the front door, or go wild and add some decorative elements to the risers with stencils. Or think of staining the door a great color and coordinate the stair railings and risers. I have an idea book put together for just such project that might spark some ideas for you. http://www.houzz.com/ideabooks/16700983/thumbs/Kathryn-Delany-s-Decorative-Stair-Risers

Your deck will be amazing. It has fantastic form and plenty of architectural interest, it will add enormous benefit to the front facade and street appeal. I love your palette, it is simple and still has point sof interest. MY suggestion would be to use a combination of your exterior colours applied where best to highlight the deck structure and either tie in, or accent against it. Ding all of these things by painting the lower retaining section in the base grey the charcoal colour to continue and blend into the lower floor brickwork, also do this charcoal on the upper deck frame which is also the roof of that entry way. I am trying to say that thick timber which trims the deck. And the slatted section of the stair wall which acts as a breezeway in the light grey- why? Because the open sections of the slats will always appear black as you can see through them to under the satirs, and the light grey slats will stand out and feature that shadow line, perhaps even use liting to further enhance this detail. Lastly, the stair treads themselves left natural, like an architectural contemporRy stAtement, the natural timber tones will be rich and sophisticated and act as art inviting you to the home. These stairs would really pop and be commentedon at street level, also consider lights in each tread, perhaps the slatted wall side to highlight both this and the stirs for night practicality. What a stunning entrance. The natural character in rich timber tones will warm the grey, keep it contemporary and not introduce personalized colour, which can take away from street appeal. This on the other hand, appeals to everyone. And greenery, landscaping will only take this to the next level. Literally!