Here are some ideas. I hope you like them!

Have you considered a shade of grey? I think something between pale and mid grey would be lovely with the dark floor and the white trim. It would compliment the rooms without trying to match them. You've gone for really beautiful strong and definite colours in both rooms (which I love) so I'd keep the hall a little more neutral as a backdrop to the green and teal.

Hi Odette! Have you had any progress with decorating? Hanging a mirror could be good in terms of light reflection and making a space seem bigger than it is. I like your idea with the photographs and horizontal lines - I might add some adjustable spotlights to make a feature out of the photographs! For e.g.

We're putting three reclaimed beams on our master bedroom ceiling. The room is 17x21 with flat 9' ceilings and the ceiling will have white ship lap running the 21' length. We will have three beams running the 17' length. Do we go with 6x6 or 8x8 beams?!? I don't want them to look skinny or like toothpicks but I don't want them to swallow up the room either and make the ceiling look lower and overpower the room. Please help!!!! Need to make a decision like yesterday!