Paint the extruding garage a feature colour and the room above a different shade of that. For the rest of the house one colour. I like what the other person said with greys. Use grey as a feature and may be a toned down white for the rest. Posts could be black or dark grey and timber slats as you thought. If you have timber slats anywhere, I would probably leave some exposed brick somewhere, that is, if you are painting or rendering the house. I like 3 different elements in a house. eg. 3 different colours or 3 different products/textures.

Yes, I agree they are fairly narrow and I think practicality must trump original design in this regard. You can still remain true to the era, and simply widening the steps to flush with width of verandah will only improve upon the original design. I believe it will also future-proof the steps as I can imagine as people age, they sometimes require the firm arm of someone else to assist them safely up and down the stairs. I have to agree with Mel about the letterbox. IF you are set on mixing styles, then perhaps use the same timber you used for the letterbox to face facade (street facing) of new steps.

Orange brick looks good with beige https://www.houzz.com.au/photos/traditional-exterior-traditional-exterior-nashville-phvw-vp~6689812 with gray with green

Geez I'm thick -- I looked at the picture , and thought the white rails were a frame for the roses ! I'm sort of with me me -- its the details that let the place down . Almost all the plants are what would have been in fashion 60 years ago , and whatever the railing is for , by painting it white it actually detracts from anything positive . Although minor , things like the gas meter or letterbox or whatever that box is at the entrance , painted in a different shade to the main brick of the house , just grates . Go and get 3 or 4 test pots , and although the bricks are a mottled effect , you'll get pretty close to the predominant brown -- the red tone of that cover is pointless IMO . If it does need steps ,then do them up through the existing garden , but basically I'd redo most of the garden . Personally I think the white on the timber is looking too bright , but although charcoal is trendy , I don't think the brick is red enough to pull that off , and I dislike buttery cream , so a very light steel blue tone on the timber including the barge boards and garage door , against the bricks , would be my 'updated' preference , BUT do the garden first IMO .