If I'm understanding your question...the bottom half of the dining room will be a high gloss white and you want a darker color on top? I think that darker gray would work. We did a darker gray under the chair rail with a lighter gray on top and I love it.

I like what you've done so far - it's going to be so light and airy!

Wow! I remember your dilemma. Great job! The only thing I am concern that you go with high glossy for the wainscoting . Are you sure? Did you do research enough about glossy paint? Usually semi-gloss goes for trim ( base board and molding).

I'd keep it consistent since you're lightening and brightening - Lazy Gray will have a great, different feel in the DR space with your wainscoting treatment happening in there for a unique moment. But yes, that wainscoting effect treatment should be semigloss, not high gloss so that it flows seamlessly with door and window casing and your adjacent base moldings.

Really interesting bones in the place - this paint adjustment is a great reset (and really balances out your floors beautifully). Cheers!

just cruious...are you doing your own painting? If so - Wow, what a job to undertake. (Says someone who has painted every surface in every place she's ever lived, often multiple times.) Good on ya!!