In my opinion, a cuckoo clock is a very detailed design, but you say you want a simple design for the room. When you say simple, are you thinking of no wallpaper, no wainscoting, and no accent color on the walls? It seems as if dark orange is a color you favor. I see it in art images and in your curtain color. If this was my space, I would paint all the walls one or two shades lighter than the beige of the sofa to keep the room as bright as possible because the room has no direct sunlight. I would paint the ceiling 1/4 (one part wall color to three parts white). I would use a satin or eggshell paint instead of matte, semi-gloss, or high-gloss paint. I see some discoloration on the wall behind the sofa where the brown color of the sofa frame has worn off onto the wall. I suggest attaching bumper dots or strips on the wood frame of the sofa (similar to the ones used to keep cabinet doors from making a lot noise when they are closed quickly). I would consider painting the sides of the column with the cuckoo clock brown to match the clock. I would do this to call attention to the clock. I would remove the orange curtains and replace them with floor-to-ceiling length draperies hung as close to the ceiling as possible to make the room seem larger and taller. I would change the drapery color to match the walls, perhaps in a muslin-like fabric, which is a casual fabric. I always take my art to a professional framer. I have conservation matting and museum glass used for my art. I would have the three images you have rearranged as a collage in a very large single frame with medium to wide matting between the images. I would have the mat and frame color(s) enhance the images, even if it is a color I might never have thought of on my own. I would hang it above the sofa. I would use the orange drapery fabric to make throw pillows for the sofas. You did not attach a photo of the flooring in the room. A medium tone floor is easier to keep looking clean than a light floor/rug or a very dark floor/rug. Other "Houzzers" will give you completely different ideas. Use the ideas YOU like and enjoy your home!

Depending how vivid your scarlet is: You can go with white or cream so it really is the accent wall and nothing is shouting for equal attention You can also go for a muted grey or beige

Embrace the arches and keep it light, but add some contrast. Paint every wall with an arch in it fresh white, all ceilings too. Paint the adjecent walls a soft color. For example; when you keep the kitchen tile, you could paint the walls above it a soft pink or mauve. I see three open areas, so you could divide those with three soft colors and white inbetween. Keep most lights simple and functional, uplights will enhance the arches, glass pendants will add warmth. And I think a soft olive or sage green is a great color for a living room.

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