Light fascia, a not quite white, but very light colour that matches the yellow house - maybe the colour on the knobs on the platform. Same light colour for the posts & rails of the deck for all except the very top hand rail leave that grey. Like the first picture in the comments. Paint the end board on the bottom stair platform the same colour as the house. Grey stairs perhaps. Leave knobs light.

horizontal anything is a no, the gap would have to be so small it might as well be solid. yes the vertical cable might pass but you are not allowed to be able to squeeze them together as then the gap distance is non complying, The safest one is the solid section PCA pool fence, or glass, or solid, to 1200 mm in Queensland, no greater than 100 mm off ground, and gaps not able to be manipulated, and to stop that you have to have horizontal section in the cable type, which then do not comply, cut metal screens if complying is OK. I would question the void, and if you know the reason for the void, than solutions will be able to be worked out, now we are asking why? Pools in adjoining yards are acceptable with pool fencing complying on both sides, no void is required. so the void sound a bit iffy, unless it is something to do with storm water, or a building requirement, so ask the question why. Pool fencing can be awesome.

Remove red shelves and build in a wall of fitted shelving on that left hand wall, extending right in along the side of the desk. I notice the filing cabinets are at either end of the desk - can they be moved to the right hand end so as not to be blocking the storage area you will have created. In fact once you have the extra shelves you may be able to get rid of one of the filing cabinets. Place the printer and extra equipment on the shelves where they cross the end of the desk, and you have all the rest of the wall for dedicated storage for books, files, rubbish bin, containers for EVERYTHING, appropriately labelled, this may help hubby to keep things tidier, eg a container for all the cords and connections, another for USBs, appropriately labeled, Lots of file boxes or other appropriate storage containers on the shelves. Install plenty of electrical sockets, or fit that power board UNDER the desk, out of the way. A charging station would be useful. Stack of fresh paper for the printer, bin for rubbish - having EASY access to EVERYTHING is the answer. And yes, hide all those cables! Wireless gadgets if possible! My desk has a half-depth shelf under it, in front of my knees, which has the printer and spare paper stacked on it. Works just fine, out of the way and accessible.

You see how horrible the green looks now ? Even the brown ? That was trendy in the 90's . Grey will go the same way , personally i feel it has . Wood is warm , the steel blue in one of the pictures is underutilised IMO , charcoal hides a multitude of sins . I'd definitely break a verandas look , with a charcoal base . I'd go with natural varnished timber verticals , and be tempted to do a lighter steel blue deck and handrails , as well as the gutters . I suspect the gutters won't even look out of place against the brown roof , as long as they look light and slightly industrial ( steel blue does that ) . You could even go as light as surfmist for the gutters / rails / deck without it looking 'funny' . The garage would be a challenge -- I'd personally try and get an orangy beige to reference the bricks , but that would be tricky . So probably settle for steel blue or surfmist or whatever shade of light silvery blue you opt for . I wonder how long your windows would last painted though -- given their age , I suspect they may have started to oxidise , even if they haven't , they would need a lot of prep . By keeping fairly light colours on your gutters . handrails etc , the windows maybe won't look too bad , as they look a relatively light golden shade . Personally , I'd consult an expert about the windows . Hopefully given you something to think about ?