Hi, I know there are so many things to take into account and it's hard to get perspective from a photo. The white you can see is an extension with building paper, and the red is the existing building which is two story. The exterior is wide weatherboard planking, the windows are silver aluminium with very little trim. The doors in the front of the picture are French doors from bedrooms that will open to an enclosed courtyard ( yet to be built of course) The roof will be a light grey/brown but you won't see it much because of the flat roof style. There will be decking and ballustrades covering half of the new extension.

If you use masonry paint, we could head in a warm greige direction for all of it - not so yellow . .. something that can give you a bit more contrast against the white windows and trim - even 40 does a lot for us . . . what about a blue green gray? You will get a coastal / mod vibe and it will relate to the farmhouse look .. .above bm silver mink http://www.benjaminmoore.com/en-us/paint-color/silvermink and below . . . gilbraltar cliffs . . http://www.benjaminmoore.com/en-us/paint-color/gibraltarcliffs Shingle look siding on the side dormers would be neat to get that cottage mod. . . you can stick with yellow but I don't think it complements the roof tone. With the blue-green grays, the white windows and trim will really pop beautifully. . . You can also go more neutral with a warm gray - greige . . . here's the siding tone http://www.benjaminmoore.com/en-us/paint-color/capemaycobblestone paired with this for brick - http://www.benjaminmoore.com/en-us/paint-color/graystone potential future red windows . . .aluminum pits over time, so if you have just one side you want to try, you don't have to powder coat, you can take a small brush and just do them by hand with latex paint if they are 10 yrs old or more. . . one advantage to gray . . future see [houzz=]

To answer your question I would paint the body of the house blue, all trim white, and then the "fringe" which I think ties into your porch decking, I would paint it the gray. It is a good "grounding" color for your home. Sherwin Williams has a cool web tool. Take a pic of your house and load it onto their site. You can "color" away on your house. When I painted my house for the first time, I did not want the garage door to stick out, wanted it to blend into the house. Everyone said it would look weird, needed to be painted the same as the trim. Used the Sherwin Williams site and realized want I visioned looked good. I have neighbors of dubious design skills! Ha! Ha!

Without knowing any more info , I'd say its near impossible for anyone but you to know what colour/s to choose -- do you want the house to blend in but have its own style , or do you want it to stand out ? What colours are your main furniture items and even kitchen etc ? For xxample , if keeping the beige walls , how about doing the eves and gutters and garage door in a tangy ( bright , but not glaring ) orange -- this would work with the existing colours and not require a complete repaint . BUT if your kitchen was mainly various shades of , say , green and teal , and your lounge suite and duvet covers were mainly blue hues , that may 'feel' funny , clashing with the exterior ? Of course , blue and beige exterior may not work with the brown aluminium , as youve recognised . Another option ( a bit hard to tell from the pictures ) is that a light grey ( repaint the beige ) with mid-charcoal base boards may work with the brown aluminium , then a bright colour on the gutters and front and rear doors to suit -- anything from sea blue to bright yellow , orange , red , even white or off-white would probably work .