My first question is What is your favorite color? You have excellent neutrals that could work with any color. If you love the cool gray green of Farrow and Ball's french gray I say go for that color. That is a color that can compliment many different colors from the gold warm tan drapes to a fire hot red chair or a deep green alligator. Go with what you like and you will be amazed that it works. If you think the Farrow and Ball French Gray is a little too green based you might consider another FB paint called Light also by FB French Gray FB Light by Farrow and Ball I like mixing cool and warm in different venues for drama. Obviously not all the colors but keeping it simple to two basic hues and working with them is ideal. You have one small wall behind your china cabinet that you could paint in a gold tan to match the drapes but the rest of the walls the Blue gray Farrow and ball you are thinking of would be perfect. Here are some combinations of gray blue and tan that look stunning. Living Pod Dining room rescue blog Clear Skies by Benjamin Moore French Gray Farrow and Ball (The color you love) French Gray FB by designer Brooke Gianetti amazing with the soft cream. Other Neutral colors if the farrow and ball is too scary for you to try Fools Gold Benjamin Moore New Penny by Valspar Blonde Benjamin Moore Skylight Farrow and Ball Camel Hair on left and Gustavian Grey Shaker Gray by Benjamin Moore

I think Milly Rey is saying what I suspect also: at some point, your house was remodeled and someone removed some walls and or elements that were intrinsic to the MCM style. The pony wall is probably not original to the house, and the railing around the stair well is definitely not original. The bi-fold doors and those contemporary white tiles are likely replacements as well. Here are some MCM entryways that are a more true to the design of that era. To emulate these, you'll want to consider installing some veritcal dividers on top of the pony wall or instead of the pony wall. Change out the railing, and put back simple slab sliding doors on the closet. Please also consider getting a new door that has some glass so that you have some natural light coming through, or, at the bare minimum, paint the door (inside and out) a bright cheerful color. Maybe one that you can use as an accent color other places in your home. A slate floor entryway was very common in homes of this era. It might be worth a consultation with an architect that specializes in restoring MCM homes. You may have some other alterations that were done to your home over time, and if you can restore it, it will probably greatly increase the value of your home. And if you're an MCM lover, it's just the right thing to do. Here are some inspiration photos you might find helpful. railing examples Vertical dividers Double doors with glass inserts and another way to divide the entryway from the living space. Sliding closet doors and a globe light are a winner here.

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Decor *and* behaviour modification; you do want both. For the wall, poi ting in the direction of the guest bathroom: https://www.etsy.com/ca/listing/605597937/bathroom-arrow-wood-sign-wood-sign-art?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=bathroom+arrow+sign&ref=sr_gallery-1-19&organic_search_click=1# https://www.etsy.com/ca/listing/571776054/sign-restroom-wedding-restroom-bathroom?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=bathroom+arrow+sign&ref=sc_gallery-1-2&plkey=a835f4c96e0b1f058d0a007059d972f86d902f4f%3A571776054# https://www.etsy.com/ca/listing/582618754/restrooms-sign-restaurant-sign-rustic?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=bathroom+arrow+sign&ref=sr_gallery-1-14&organic_search_click=1&pro=1# And for your bedroom door:https://www.etsy.com/ca/listing/629668772/personalized-mr-mrs-last-name-sign?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=mr+and+mrs+wall+sign&ref=sc_gallery-1-15&plkey=a6232108a973c10b6ddf8a400760c56398f916e6%3A629668772&cas=1#