As the appearance of the garden has a modernist style with the straight lines and concrete furniture how about a Mondrian influence and add a bold strip of blue? It is a pond and with the right shade it could look really relaxed and contemporary. My daughter's suggestion is a chalky lilac!

I'd match the white of the door trim and baseboards.

This just popped up , but I see it is quite old . Did you decide on paint colours ? The roof looks almost a brown tone in the photos , but you say it is dark grey . I assume you don't want to paint that ? If you do , go more charcoal IMO . If you don't , I'm assumimg it will look several shades darker with your wall colour choices . There is a roller door on the garage that appears to be a nice shade of orangey yellow . Personally , I would go with your colour choices , but do all the doors ( roller doors , wooden doors ) and gutterings in that ochre shade . Your terrace I would do in a charcoal , but with the top rail either in the orangey yellow , or a really crisp white . I know that sounds a bit 70's ( although they would have added a lot of ranch brown back then haha ! ) but against the light grey I suspect it would work together well , and look the part .

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 .