As the appearance of the garden has a modernist style with the straight lines and concrete furniture how about a Mondrian influence and add a bold strip of blue? It is a pond and with the right shade it could look really relaxed and contemporary. My daughter's suggestion is a chalky lilac!

Wow, that was awesome Mark, thanks for that and everyone else. I thought about the desk facing the other way actually, to avoid feeling enclosed I do have really great views there so I thought about a small couch and maybe a bookshelf on the back, but having the dining table in front is probably not the best either.... complicated :( Here are a couple more pics, today was a beautiful day so I managed to get more of the views

My vote is for the wash but not in bright white and after some selective knot primer in the same tone. You are going to want to selectively primer down about 2/3 of the knots (use a dark white tinted primer), and use a dark white / brown toned off white instead of bright white so the beams still give you dark white on bright - that would be my vote. Consider something like bm stingray tinted primer and wash on the beams. You can add glaze for more working time or put down dropcloths and use water to cut it into a wash. Test it on some other raw wood that has had tannins develop for a few years. Then put it against your white wall - your husband will get the contrast and wood grain but you'll get the quiet palette you were hoping for. They both will have architectural depth and interest.

We just stained our section fences with Wattle Ebony from Mitre 10. Was looking for a charcoal color too, not much flexibility in color options with stains from the shelves at store. We sprayed on, rather than brushing. Is cost a concern? One of our to be neighbours was doing there fences at the same time with paint, he said he used nearly 100L of paint for 2 coats, we used nearly 50L in 2 costs - had similar amount of fences. I've included photo of it after the 2 coats