help! decor advice needed!

hey all, so i am bouncing back and forth between projects in this house; the yard, the living room, the dining room.  but right now i am thinking about painting the dining room.  i'd love to paint it a dark and moody blue-ish gray-ish color and eventually install some wainscotting around the bottom half of the wall like this:

from those inspiration pictures above you can see i'm still undecided between gray and dark blue, but i'm leaning more towards a dark blue or teal color i think.

but the issue that i have is that two of the walls actually connect to the front room and a third wall connects to the hallway.  so that would mean that i would need to paint those walls all one color, and i don't know if i want the dark color for the dining room to also be in the front room and definitely don't want it in the hallway.  here is a picture to demonstrate what i am talking about:

the wall there in front of us continues off to the right of the photo, into the front room

and then the opposite wall also extends a little into the front room

and then the adjacent wall is shared with the hallway

here is the view of the smaller wall from the front room

here is the longer wall that the dining room and front room share, from the view of the front room

so there's nothing that visually breaks up the continuous wall from the front room and dining room.  i was thinking of ways i could make a visual separation by maybe adding some vertical trim, but i think it would look awkward, especially since there is already the railing there.  i fear that it would look too visually cluttered.  and i really don't like the idea of simply stopping one color abruptly and starting a new color.  so, what do you think?  how can i add a visual line of demarcation if you will on one continuous wall that the dining and front rooms share?  i've googled this and am not really happy with any of the options i found online.  suggestions please!!!  thank you!!!!!!!!