I think you need to do one color. The line never looks right.

keep to one color.

Not only will the line not look right but one color will make the room feel so much bigger. I have been seeing a lot of places on the East Coast (and this look I believe started in Europe) where they also paint all the trim the same color of the walls.This makes you able to have jazzier accent pieces (painting, pillows etc.) without it all looking too busy. There are nice features here, a built in, arches and a fireplace - they don't have to be different colors to get the great effect they have.

One color.

Paint the entire arch, both sides & underside, the same color as the living space. Paint the dining room walls the separate color.

I suggest using one neutral color for the entire space. It really is one room, by definition. A color transition would be distracting to the eye. You can achieve different personalities for the spaces through different bold colors in accessories, window dressings and furniture styles.

How about painting each room in whichever color you pick, including the arch on each side, but painting the underside of the arch in a neutral and continuing the arch (visually) to the floor with a vertical stripe that's the same width as the interior of the arch?

I'm not sure what color you would need to make it work but the wider neutral stripe would be better than just having two colors smash up against each other somewhere.

I think you should use colors in the same palette, for example, your dining room gets alot of natural light, if you aren't planning on using heavy drapes or curtains I would do a darker color, then possibly one shade lighter in the living room. So the colors are in the same 'family' and will compliment each other well.
Regarding "the line" I would paint the archway as part of each room. Paint one side the dining room color, the other side, the living room color. OR you could leave it the same color as your trim. Either way, it's a great space!

What about a common color for the long walls and the underside of the arch, and two different colors on the short walls and facing sides of the arch as accents? That way you can pull all three colors into both spaces, and make a really cohesive space. Maybe something like a light taupe as the main color, with a peacock dining room wall and an olive-y living room wall? (Or whatever blows your skirt up.)
There actually is an old rule about painting the underside of arches like that. You should use the color of the room that serves as the lead in to the next room the majority of the time. That is to say, if you more often go from the living room to the dining room, as opposed to the other way around, you should use the living room color. If you do the three color scheme, I would suggest painting the underside the color of the long walls.

I agree. I think the only other way you could get by with two colors would be to somehow extend the arch to the floor, with plaster or something, and then you'd have a dividing line. But then, you'd have to answer the question of what color to paint the arch.

Paint the trim in the coordinating color? Or ceiling? Or ceilings different colors in each room? Really don't know how any of it would look. I think you should use one of the various paint programs that companies like Benjamin Moore and others have. There have been links posted here in the past.

If you're keen to have 2 separate areas I'd suggest perhaps using neutral voile curtains to seperate the 2 spaces from each other... Whilst it would still allow the light to travel through both areas it would give you enough definition and hide the awkward painted line that would be there...

If you really want to have the two rooms be different colors, I would paint the entire arch the white of the woodwork, and even have the width of it extend down to the floor with masked off lines.

OR, if you're feeling bold, paint either side of the arch the color of its room, and paint the underside of it (plus I would still do the fake line width extensions along the walls) in a totally different color.

I'm not sure there's a good solution :(

I'd instead use a single color, but paint the molding and the underside of the arch in an accent color.

I would paint the walls that have the arch attached one color and the other two something to coordinate. The other (smaller) two don't necessarily need to be the same color.

I agree that painting both rooms the same color will provide the best visual flow. If you want to introduce a second paint color, put it on the recessed back wall of the dining room with the built in.

If you really want two colors, you could consider adding a chair rail under the arch so that there is a defined end point. Then paint the area below the chair rail the same color. But I agree with the other posters, one color with possibly an accent wall in the dining area or one color with a complementary color for both ceilings is the way to go.

We have an archway painted by the former owners of our house - the underside of the arch, and everything to one side, is taupe, and the other side is sage. The darker color is on the "shadier" side of the arch, and continues on into the next room.

Wonder what it would look like to have a simple, faux (half-) column on the wall at the base of the arch? Then it would be a visual boundary where you could end one color and start the next. Or just paint the underside of the arch the second color, all the way down to the floor as if it continued, and have a plant or small table there to camouflage the transition. :)

Looking at the picture again and where the arch ends, a chair rail would be way too high. I think sticking with one color would be your best option.

I have a similar room and if you choose the right colors, it will look great if you let the arc act as the natural line in the room. Paint the underside and the side closest to the living room all in the living room color. Paint the dining room its own color with just the dining-room-side of the arc that color. Hope that was helpful and clear enough :) Great room!

I would keep the woodwork white/near white, paint all the walls a light to light-medium value color and paint the far dining room wall with the white cabinet a deeper value of your chosen color. I think painting the spaces two different colors would be too "busy". Bring different colors into each space with your accents.

I agree with evansal3 - I did this in my house in a couple of different areas and it looks great. Don't be afraid of it - even if the colors are very different from each other, as long as it is well painted, it will look good.

I've had to deal with this in showroom where I work when I have one large room that is broken into 2 or more smaller settings with different paint colors. We usually take the paint color to a doorway and then leave the area just above the door white. Then, after the doorway, move onto the next color. It sounds crazy, but it actually looks nice. I'll post a picture on my blog later so you can see what it looks like.

www.christineschwalmdesign.com

I would paint the room one color, but paint the arch in a lighter or dark shade, but in the same color family.

You could consider painting the two long walls all the way through the dining and living rooms one color, and the painting the two end walls, and the arch another. You could also paint both rooms all one color, and paint just the arch the accent.

Do one side one color, the other side another color, and then paint the underside of the arch it's own color. I'm seen this done very beautifully, but you have to be sure to choose the right color combination.

Pretty much as stated above, if it were me I would pick one color to paint the long arch walls in both rooms and use one or two colors (depending on what you have picked out already) as the short end walls. That way you get your color pop without creating an awkward line at the arch. But to really answer your question, paint each room the color you have chosen. Then paint the entire arch (up to the ceiling both sides) the trim color. Then extend the arch lines down to the floor in the trim color as a separation. I think having the entire arch painted will make it pop, provide a clear, distinct separation between the two colors and look great. Follow up with a pick with whatever you choose!

I definitely think you can pull off two colors. (Just one -blah!) I like dash's idea best (paint the whole arch, both sides and underside the same color as the living room, and then a different coordinating color for the dining room.) I would not, under any circumstances, paint the arch a third contrasting/trim color, and definitely would not paint only the underside a new color.

If you really want two different colors you'd have to somehow extend the arch down to the floor to separate the rooms. Maybe you could just put some wooden molding?

I think some of the commenters are missing the fact that you'll need a dividing line no matter what due to the design of the arch. If you can't live with one color, I like miratime's idea, painting a wide stripe to the floor. I would do it in a contrasty color so it really stands out and looks intentional. I would keep the whole space one color but do an accent wall at the end of the dining room if you really want that additional color. Cool space!

one color for the entire space

if you're craving some variety, it looks as if you might have an opportunity for a nice accent color at the back wall of the dining space, below where it's framed by the soffit

1 color

I'm on board with the single color for all the walls - but you should paint the ENTIRE arch detail (both sides & bottom) the 2nd/coordinating color. I wish I had your apartment's details.

One color for both rooms, but paint the arch itself in an accent hue.

I had a space similar to this and one color always worked best. When I did experiment with a second color I always had the color from the larger, open room on the underside of the arch. I think painting the back wall in the dining room is a good solution to bring in color while keeping the rest of the space unified by a predominant one.

I agree with NYgirl that you should paint the walls one color, then paint the arch itself a different color. This will showcase the unique architectural feature, plus solve the problem of the color line. You can go tone on tone for your color choice or a little bolder and pick two complimentary colors. Your window treatments are another great place to pull some color into the space.

I have to chip in with all the others who think this space is best served with one unifying color. Right now, it feels so open and airy and I'd hate to lose that quality with the busyness of two colors --- especially with the architectural detail. At the most I might paint what appears to be a niche in the dining room.

NO!!! Don't do it!!! stick to one color, you don't live in a huge palace, you live in an apartment. Stick to ONE color only!!! I would suggest a nice soft white on the walls and a softer color on the ceiling if you want to play with SOME color.

If it were my place, I would keep the existing wall color and paint the ceiling different colors in different rooms. It's so bright and airy now. The dark curtains look out of place, but it would be beautiful with white linen roman shades.

what a freaking cool feature.

I'd live with it a while, then if you still want more than one color, consider using slightly lighter/darker shades of the same color from the same paint chip card. Maybe the lightest in the LR, the darkest in the DR, and the arch somewhere in the middle?

Great space - It all wants to be one color.

BTW - The curtains on either side of the fireplace:
They either need to be alot shorter or alot longer...

I agree with keeping the space one color and possibly painting just the arch with an accent color.

I know this is not your furniture, but adding area rugs, even if you only doing one in the living room and leave the dining room bare, will really help to define the space and potentially add the color you are looking for.

Love the space. Keep all the same color including the ceiling and trim. It will look much more elegant and larger.

Just use a semi gloss on the trim and I would use satin paint on the ceiling to get some reflective light on the ceiling.
One idea would be to paint the built in cabinet in the dining room a nice grey or grey green depending on your color palette.

One color. Or, if you must have two colors, continue the arch to the floor with trim and paint the entire accent a color of its own.

If I understand your question correctly, the problem is that the boundary marker, the arch, only goes down halfway leaving no place to stop one color and begin another. I'd suggest using architecturally fitting trim to extend the arch trim down to the floor. Then you have a clear stopping point for the paint color for each room.

I'm not sure why so many people advocate one color. Two light colors that look nice together could look fabulous! Good luck!

another option, paint the "divider" the same color as the trim (gloss white?).

First off, I want to say what a great apartment that is! I'm from Berkeley, so I'm just imagining this place in some lovely area, and it makes me very glad I'm going home for the holidays. :)

OK... now... I do think two colors can work. I've seen it done before, and I've always thought it looked nice. I think this is a large, light enough space that you can work it nicely. I would paint either side of the archway the color of the room that it is facing towards. Paint the underside of it the lighter of the two colors. Then, draw the color line down the middle of arch where it hits the wall. And I agree that they should be in the same family. That said, I love the airiness of the light paint that is there now, and one color certainly will help the space seem more unified and possibly larger. I think the call on that depends on whether you want it to seem cozy or big and airy. The two paint colors idea will also look better with a more traditional look, while the single color seems more modern to me. I hope that is helpful! Good luck, and enjoy your new home!

I've seen people try to split rooms like this, and I'm afraid it will always look better as just one colour.

For it to look like 2 rooms, you need wood trim around the opening, and for it to look like doors would fit the opening. (Even if you don't have doors). If you have the budget, pocket doors are quite nice, and handy if you need to separate the rooms for overnight guests, etc. I have pocket doors in my similar rooms. My rooms are different colours, and the one has wainscotting and other does not. It looks fine because they read as 2 separate rooms with a large doorway.

You can get moulding or thin fence boards (about 1/2")the same width as the arch support and simply extend it to the floor. That becomes your line - the whole arch bottom-side and supports as one color, probably your trim color. This, plus two paint colors, make two rooms, not one.

You'll also need to get floor moulding that matches the existing trim and cut it to go around the new supports, but that's not a lot of work if you have the right tools.

You have one continuous wall that runs through the dining and living areas; there is no graceful way to divide the rooms without re-doing the arch (which would be destroying an attractive architectural feature, and which your landlord would not support).

A painted (or unpainted, as others have suggested) division or applied trim would just look awkward. Really, it would.

The best suggestion at differentiating the rooms through colour is by painting the ceiling. It is actually starting to come into vogue right now -- as is applying wallpaper on the ceiling (have seen beautiful wallpapered ceilings lately!). A light blue in one room, and orchid or light green in the other would be lovely. As would silver leaf on one ceiling, and gold on the other. Or perhaps a high gloss bright turquoise on one ceiling, and orange on the other (almost a patent leather quality). Check out the orange walls of this dining room -- 12 coats of Benjamin Moore's Electric Orange, with 2 coats of glaze:

http://colourmehappyblog.blogspot.com/2009/12/victoria-websters-renegade-regency-top.html

Or some sort of wallpaper...

Maybe lincrusta
http://www.designyourwall.com/store/Ceiling-Lincrusta-Amelia-paintable-wallpaper-RDD1956-pr-1588.html

Or custom ceiling wallpaper
http://www.outblush.com/women/home/art-decor/ceiling-wallpaper-/

Or beautiful, delicate, subtle wallpaper from elitis:
http://www.elitis.fr/
Check out the Japanese Straws, Sophisticated Materials, Extra Wide Fabrics, Mineral/Glass Nacres, Vegetal

Or maybe a damask or flocked paper (in perhaps
http://www.housetohome.co.uk/galleries/bedroom/Decorative_ceiling_bedroom_10245.html?subslug=

Or a metallic Brunshwig et Fils wallpaper
(check out the dining room ceiling)
http://colourmehappyblog.blogspot.com/2009/12/victoria-websters-renegade-regency-top.html

Think outside the box, and you can make your living and dining area truly gorgeous... the kind of gorgeous look that simply painting the walls cannot achieve.

p.s. a piece of unsolicited advice: your dining room table should be centered under the chandelier, which should be 30" above the table.

I used two shades of the same color (darker in the room with more light) and painted the underside of the archway the same color as the trim.

Hmmm, the devil on my shoulder says this is the time to experiment with homemade gradients!!! Bwahahahaha >:)

I ditto RoxiGirl's idea.

It would look silly to have a break in the color...perhaps you could pick one continuous color, then settle by doing an accent wall on the far-side of the dining room (an eye-catching wallpaper would be nice!) ? It would really bring out your beautiful built-ins.

How about this: Rather than having the two rooms' colors smash up against each other, paint an accent wall in the kitchen. You could also paint the ceiling and have the ceiling color extend to the arch. But I agree that without any kind of molding or barrier between the rooms, it will look really awkward. If you want the living room to have a little something different, you could use a different accent color on the molding. I'm not necessarily suggesting that you use all of these ideas together, but I do think if you paint the far wall of the kitchen, plus the molding in the living room, you can achieve two different but cohesive looks.

I like the idea of doing the living room and whole arch in one color, and then you'd have an accent arch of living room color facing into the dining room area, which I'd do in something complimentary- I think it would look really fascinating.

For instance, I'm imagining that space with a cream trim, grey blue living room (and arch!) and medium grey dining area, with very light yellow curtains in both rooms and floofy white or deep red turkish rugs . But that's how I roll- I like bright color and I don't give a bleep if its too much for other people.

I also think it's just paint, and that space is a absolutely beautiful blank palette so it would be sort of sad if you play too safe and then never see how far you can push it. I think the only two things that I would never try would be to make the arch a different color from any of the walls it touches or to split the paint in the underside of the arch. And even saying that I bet someone talented could make those work.

If the main goal is to play up the shape of the arch, I think that you could use 3 shades right next to each other of one color from the same chip of whatever color you like best.

Paint the middle one of the two on the walls that the arch is on and on that underside.

THEN... on the living room side of the arch itself (which actually seems to be a darker room, emphasize that dark moodiness slightly by painting the darker of the 3 shades on that side of the arch and surrounding the living room windows.

THEN... on the dining room side of the arch itself (which actually seems more sun-drenched anyway, emphasize the bright light of it all by painting that side of the arch the lighter of the 3 colors, and using that same lighter color on the far wall of the dining room.

This way, both rooms seem to be painted one even consistent color, and yet they still feel somehow different and the value difference will always make the interesting shape of the arch itself contract with what's behind it.

I hope you'll consider something like that.

one color only!

Here's what I mean; have a look:

http://www.flickr.com/photos/artycurtis/4189744480/

It won't be radical, but it will give a different mood to each of the 2 rooms, almost as if you had done it with lighting.

Judy, I'm thrilled to say that I had the same problem three years ago when I remodeled my kitchen. We added an arch between the kitchen and dining room, but I didn't want to paint the rooms the same color. So here's what I did:

I painted my kitchen a light blue-grey and my dining room a spring green. Each side of the arch corresponded to the color of the room it faced. The underside of the arch I painted in the lighter color (blue-grey). Now for the tricky part- what to do with the split in colors on the walls. Instead of going vertical, I split the colors horizontally. So, in your room, you would have a divide in colors going from the bottom edge of the arch to the fireplace. Sounds funny I know, but the divide will frame your window and chair nicely (and maybe get rid of curtains so it doesn't create a break in the divide).

If you'd like to see a picture of my solution, just email me through my blog.

Oh, and whatever you do, don't just paint the arch. It'll make it too heavy with the white walls.

I go with the popular vote - one color.

For 2 colors you could have a simple face of a column, from the end of the arch to the floor. Just a flat panel, 1/2 inch thick, kinda like wainscoating, same width as the arch. This way you have an element separating both rooms, no line dividing the colors.

Something kinda like in this link, but simple, very plain, like the arch itself. What you're really looking for is just a little relief/thickness to divide both rooms:
http://elitetrimworks.com/home.php?cat=102

But I'd stick to one color and paint the arch lighter than the wall color.

I'd try something a little different and make a real feature of that lovely arch.

Paint the side walls all the same color in both rooms - the lightest of the three tones. Paint the entire arch - both sides - in the next darkest shade you've chosen. Then paint the back wall in the most saturated color you've chosen. Depending on the shades you've chosen, you migtht paint the window frames the same color as the arch. Admittedly, I'm picturing this with cream walls, soft cafe au lait arch and window frames and an expresso wall at the end of the dining room, OR cream walls, a soft powder pink arch and window frames and a deep raspberry wall in the dining room.

Whatever you do, that is a gorgeous space!