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.

To minimise costs, frame your windows, I would place a canopy above the front door (if this is the front door near the garage - if it isn't don't do) to draw your eye and paint the front door with strong wow colour - even if it is a few shades darker or lighter to what you have chosen for your window trims/roof line. Maybe large number near door also will drawn your eye to the door. Landscaping around the front will also add punch/wow - you don't have to do everywhere - but at least at the front and then you can work your way to the rest of the garden, but keep the rest of the lawn mowed (even if they are weeds) and edges trimmed. Look at a couple of other houses and pretend you might buy and note what your eye is instantly drawn to... go back to your house and note what you are instantly drawn to.... do you want to be drawn to those features? If not, make them blend and highlight the areas you want. I have just had another look at your photos - is the front door near the garage door or it is the one on the left hand...... if left hand don't place canopy at the garage end but would place some large planters (large plants too) to accentuate the front door entrance - you would have the space - but again do some landscaping in that area (the large pots can be placed in the garden beds (on a large paver) and smaller plantings around them, make the front door pop and place something i.e. large number on the wall next to the door. If the door next to garage is garage entrance not front door, then blend that door with the exterior (unlike what I had initially said when I first thought it was the front door). Tip - Just cause something is colourbond - you CAN paint it - don't think you are stuck with that initial colour thought when installed. i.e. paint your facia and gutter same colour and that will make it wider. (I have personally painted cutters and downpipes many times (when I want to change colouring). Just cause downpipes are connected to your guttering doesn't mean they need to be the same colour - I would colour them the same as the wall colour to make them blend - downpipes are not a feature. Good thing about paint, you can paint it again. A lot of paint shops will have colour consultants.

I think the red roof and teal trim suit the style of your house but do agree with the majority that the walls would look much better white. I also think that getting rid of the colonial finial and your dated screen doors as someone else suggested, would improve the look. No one has mentioned this but I do think that your terracotta tiled stairs are a jarring note. Don't know if anything can be done about this as I don't know if paving paint on tiles is successful. I think they would look better dark charcoal. Your garden edging would look better charcoal as well and this being concrete can be successfully painted with paving paint. Or will these gardens be ripped out to build the pool?

I'm not familiar with these colors but try and keep them similar i.e. A blue grey, a green grey, yellow grey etc. that might help a little bit when thinking about your choice. Also I would do the same colour as you use on the render, (bricks) on the weatherboard above the garage or if you aren't keen on that, make it lighter. I would not go darker up higher. I would however do a very dark fence, assume the concrete one on the left. The other option, as it looks like you are embarking on quite a large project, is to change the existing colours i.e. garage door. I would choose a colour for the garage door which matches with the main house colour. Go with your gut! Good luck.