I have miles of decking at two houses. All timber when put in the Australian sun will suffer. When building our beach house we decided to go for Spotted Gum and let it grey. Why fight it? We applied Cutek, and will on a regular basis. At our main house we have lots of Merabu or Quilla. Will not grey the same, and leaches lots of red stain. Cheap, but would not use again. What ever you use, use a good quality oil that seeps deep into the wood not a traditional stain/or top finishing product.

Are they structural or decorative? If not structural it could be time to remove them and replaster a more contemporary ceiling. Or you could clad them in a gorgeous recycled timber to give them a more organic solid look. Easiest way would be to continue the charcoal paint to the beams... but lighten the feature wall to a complimentary steely gray. Some chunky timber shelves either side of the stonework with books, ornaments and lighter pictures with a pop of colour will soften it.

Just the pendant lights like Cordony Designs suggested. I don't think the existing ones tie in with the country style. Yes I like the timber beam, it looks more honey colour to me than orange.

I came across your post and I think we have the same house! I was just pondering whether to paint or not. What was your verdict on painting the beams? I was leaning toward preserving the mission brown.