I do agree about the detail being brought out a bit. Have you tried Annie Sloan's line of paints and waxes? We have a store near here that gives classes and I joined a Facebook page called something like the Painted Lady and they have great sample pics of two waxes they use over their paint. The dark wax really brings out the detail. You have to use the clear one over the paint if you want to be able to better manipulate the depth of the wax detail, but love how it looks when done.

What a pretty room. I also think the urn is too large for the table, and it looks good in front of the mirror. Other suggestions - the pair of lamps on the sideboard should be moved in a bit, so that the outer edges of the shades do not hang over the edge of the table. I think they could also come towards the front of the table just a tad. Not centered, front to back, but not pushed back so far. I would also pull the chairs on either side closer to the buffet. Doing these things allows the pieces to relate to each other more than they are now. The first thing that grabs my attention when I look at your pictures are all the pairs seemingly in a row - lamps, silver pumpkins, candle votives. When you change out the sconces, use art in those areas. Pull more blue and gold (not silver) from the peacock art if you're trying to keep the room more monochromatic. But my next purchase would be a beautiful rug, then more art. What color are the walls? It's a beautiful color. The room has a romantic vibe going. How would you feel about painting the ceiling a cut down version of the wall color?

Adding to my dilemma is the fact that this sideboard/buffet will be seen from several rooms due to the layout of the house, and because the dining room has so many architectural details, I feel that it needs to be fairly simple so it’s not competing with the elements in the room. I kinda like this, even though I’m not into MCM generally. I think the dark knobs make it work well with my dark wood dining room table.

Now that I see that cool nook.... what about going a different direction and get a simple white or wood credenza, but bring the amazing pop of color through wallpaper or tile above it. And make a bar area, or just a beautiful feature area. There are a million beautiful blue tiles that frequently get recommended on this site - often from Fireclay -- but of course I can't find any of those posts now! But here's one I found on their webpage. Not the best representation, but gives you an idea. https://www.fireclaytile.com/gallery/detail/blue-velvet-kite-backsplash Or wallpaper bar nook like this (but different wallpaper for your space, obviously). Check Graham Brown for wallpapers. Like this: https://www.grahambrown.com/us/balance-navy-and-gold-wallpaper/106757-master.html#start=11&cgid=collection-lagom-full or this: https://www.grahambrown.com/us/prism-navy-and-gold-wallpaper/104742-master.html