Led lighting running on both sides of each of the beams - you can buy it in strips. I would go for a bright white but you can even get it in colours and or changing colours. I would also do the same along the floor under the cabinets and perhaps between the upper cabinets and bench top.

ie is there any benefit in particular to have ceiling white paint?

No, sorry. Can't help. But if you copy and paste your answer in the Australian forum you may get more responses. If this is in the nz forum, aussies can't see it, but we see nz and Australia if we click nz as the country, in settings

I'm thinking of using hydrapanel in the bathroom but how do you get jointers to line up on an angled ceiling, When I say that I mean at the ends of the sheet where the ceiling meets the wall (where the fan is as its not a right angle. It's doing my head in, I can't get hold of anyone from the company and can't start till I figure it out. Thanks in advance for any help.