Yes, I agree. It has a warmer tone than the rest.

I like the darker one :)

Do you have a pic if the rest if the room do you have a big window in that room ?

I like the lightest one. The third one appears purpley to me, and the darkest color is taking on cocoa hues.

I like the lightest one on the right

Oh, the dark one for me, I think it gives more richness ;) First one.

Darkest one .. very dramatic ...

Can you provide some photos of the dining table and chairs that you are / will be using?

[houzz= https://www.houzz.com/photos/2011-hhl-dining-room-transitional-dining-room-phvw-vp~136047]

Lighter one on right

Have you thought about adding picture frame molding for below the chair rail, then painting that white and going dark gray for the wall above the rail? It's another thought...
Were u going to only paint below the rail? If so, I wouldn't go too dark with the gray for now simply because the room will be visually too bottom heavy, IMO...good luck!