Yes, same colour in different textures will provide consistency throughout with just enough variance to make it look interesting. Are you repainting your walls, if so and if you have the time I'd recommend buying sample pots of the whites you're interested in and painting a decent size swatch of them on walls to see their colour change under different lighting- it will look one colour while still wet in the tin, but completely different once dry on a wall under your house lights and the changing daylight. If it's strictly trim you're painting then that's not really necessary. Can't wait to see the end result, the dark beams with lighter trims throughout the house will look absolutely magnificent.

You never mentioned your budget that you're willing to spend. You could add a thicker fill backed insulation blanket - 50mm, 75mm or 100mm are the common thicknesses. Steep roof pitch so would need scaffolding, harnesses, etc.. which adds up quickly. Probably still not enough insulation though but probably cheapest option. Insulation under existing timber linings then reline over the top of that as some have suggested. Working at height though so would need scaffold set up again and working overhead is not fun nor easy. You could replace the roof with a sandwich panel roof. Try Versiclad or Kingspan or comparable. They have a polystyrene type of insulation between an outer metal roof sheet and a metal inner sheet. These are heat laminated together. Again different thickness available from 50mm up to 180mm is common. The 180mm has a R rating of 4.7 which is quite good. Again steep pitch, etc., probably need new ridge capping, etc.. Probably most expensive option...... Keep us all posted on your decision though!

We did pressed metal splashbacks on a display in a kitchen showroom I used to manage, and as such many of our clients opted for the same look. Powder Coated is definitely the way to go. It stands up really well for durability and is in fact relatively easy to clean compared to many splashbacks. Often people think that glass or stainless steel are the easiest for cleaning, but due to being such a flat reflective surface they show up every splash and if you're going to clean them you really have to clean the full length of splashback. The textured surface of the pressed metal means that it doesn't reflect the same amount of light so you are able to get away with cleaning it less often, and you can also get away with just cleaning the dirty area rather than the full length. The biggest difficulty we found was getting the splashbacks installed as there aren't really any tradesmen who specialize in fitting pressed metal, and those that were willing to cut & fit it were concerned about what would happen if they damaged the paintwork. We had the panels cut to size first before they were powder coated to minimize the risk of chipping the surface.

Thank you so much, Julie. I thought you would be interested in the end result, given how much encouragement and advice you so generously gave me. :-) I do love it. It has made such a difference and I think (fingers crossed) the landscaping will give it the finishing touch. We are reroofing the pergola, so will post photos when that is completed. The gazebo looks great after its facelift, too.