All the suggestions above are perfectly good. However, when you have a house that is entirely painted, the options are so endless that it's easy to get stuck. I'd advise either finding photos of comparable homes in colors that you really love, and reproducing a similar palette on your home… or upload a picture of your house to a colorizing site, and play around with various combos. Sherwin Williams has a Color Visualizer that is decent. I don't mind a white house, but feel that the black trim is a bit harsh. On the railing especially- it feels like it is outlining itself too much. Reduce the contrast between the body and the rail and it will enhance the house rather than overwhelm it. You have a lot of choices, so just experiment and go with what resonates with you.

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 .

Bump

There is no common link, no continuity that each dwelling share. i would introduce an element to both structures, borrowed fm the other, so for example the red brick and windows are the most striking design elements in the house, however the rendered garage with a parapet and no visible roof may as well be from another planet, I would brick up the front piers aside the door, with matching red brick, and then I'd install some post and beam rafters that could extend over beyond the garage door, almost like a flat eave, however just beams, no roof, and paint it chacoal, I'd then link a path from th garage to the house, and create the same detail at the porch entry of the home, same beams, colour and materials, so it looks like they belong on the same property. also, perhaps a little scary to consider, i would render the wall in between the door and the first window only, and paint the front door in the matching blue. Windows I'd go charcoal as per th beam structure, and apply a stained timber batten to the flat parapet above the garage, so paint that black, then fix timber battens vertically wh enough spacing to see that black shadowline, it will modernise it, emphasising the elongated design, which is both contemporary and popular, and tie this timber detail into the house with a generous deck. Both timbers will link, over scale th deck, perhaps stagger a step or two, as the garage is over scaled also. remove the fence, and landscape the corner with over scaled shrubbery, a meandering path to help invite ppl between the two structures., the visual disconnection is the fence, but it translates into everything else. if a fence must be, then consider a half height one, or an informal row of sleepers as uprights, to softly define the yard.