Wow - Two black & white bathrooms with mint green paint in one week!
Is there an epidemic?

I would stick with the black and white theme - paint the top half of your bathroom white, window and mirror border in a glossy black. The green tile adds a nice color contrast.. Some easy changes that would work with your room and won't cost much. If you are feeling ambitious - a different light fixture above the mirror in black - Good luck!

First thought is that you desperately need a new shower curtain. I have an even smaller bathroom, with the same black-checkered floor (and black-checkered tile on the walls!) and bought this gorgeous, light curtain for the bath:

http://www.target.com/gp/detail.html/184-5042948-1985565?asin=B000Y9YT7W&AFID=Froogle_df&LNM=|B000Y9YT7W&CPNG=home&ref=tgt_adv_XSG10001

I absolutely LOVE it, and it's extremely sturdy. The hooks that come with it are beautiful too. You don't want something dark, but the BROWN really ads a lot to a space, especially with a "mint green" base.

A dark brown picture frame, with something colorful inside, on the wall next to the window might be just what you need for a neutral punch! You could also do small, dark brown shelves for the corner, so other colorful items could be displayed.

:) Good luck!

My first thought was blackon the upper walls, for a dramatic look. You could also develop a palette of black, white, the jade green from your tile, plus a chartreuse and turquoise for a fresh, fun feel. Introduce it in a big way with a new shower curtain, some art, and a roller shade trimmed in colorful ribbon. Good luck!

Paint the wall a shade of orange that will complement the green, and add textiles with those two colors in them.

Green and brown also work.

I don't recommend orange, green, or yellow for the bathroom walls, ever. I am liking the above suggestions for a dramatic black and white - then maybe add some jade green accents. I really like dwelement's suggestion for black walls, which I would be terrified to do.

I couldn't find anything great to exactly match that green tile, but I think a new shower curtain would make a huge difference.

A strong floral shower curtain would draw attention away from the green tiles and allow you to bring in smaller colored accents (towels, a small window curtain, etc) that could stand up against such a strong floor. I'd definitely recommend repainting though - you need something bolder to draw the eye away from the green tiles. Pull your colors from the shower curtain - if you pick the first curtain, you could go with red, darker green, yellow, or even the lighter blue color for the upper wall area.

http://www.potterybarn.com/products/sophia-organic-shower-curtain/?pkey=cshower-curtains

http://www.kmart.com/shc/s/p_10151_10104_048V001536882000P?vName=Bed %26 Bath&cName=Bath Essentials&sName=Shower Curtains %26 Accessories&prdNo=4

If that's too much of a statement for you, you could re-emphasize the black & white color scheme and simply embrace the green tile by painting the upper wall to exactly match.

http://www.kmart.com/shc/s/p_10151_10104_322000XANTON008FP?vName=Bed %26 Bath&cName=Bath Essentials&sName=Shower Curtains %26 Accessories&prdNo=26

http://www.kmart.com/shc/s/p_10151_10104_048W015699640001P?vName=Bed %26 Bath&cName=Bath Essentials&sName=Shower Curtains %26 Accessories&prdNo=46

http://www.kmart.com/shc/s/p_10151_10104_09647240000P?vName=Bed %26 Bath&cName=Bath Essentials&sName=Shower Curtains %26 Accessories&prdNo=59

Wow, so many great ideas! The hubby doesn't love the idea of painting the trim black. Darn! I'll make sure to post a before and aft when we change the colour. Thanks again! Christine

I would go complimentary. Red compliments green, and with this shade of green I'd probably go azalea or rose red (i.e., slightly pinkish, but a darker shade).

Could be done with paint, or it could be done with decals or stencils. A shower curtain that adds some of this color would help too.

Light grey.

I agree with mattab, gray would be great, but a green/gray. A white shower curtain with gray border or accent, and towels in gray and green.

I third the pale grey. I'd say show restraint with colour and pattern but instead create a mood. The black and white floor tile remind me of a moody Parisian tabac or coffee shop. Why not check out a second-hand shop for a worn looking mirror with an interesting frame? An old shaving set or a simple glass soap holder could carry theme through. I think the more unpolished the items the better.

How about trying to hang a plant to the left of the window, nearly above the john?

Also, without too much effort a Marimekko shower curtain would give the space the pizzaz you might be looking for...

http://www.amazon.com/Marimekko-Kaiku-Shower-Curtain/dp/B0018KNX1E

Whatever your choice of paint - make sure it's something that complements your skin tone. Green, yellow, orange, not such good effects.

I would play up the green aspect, replace bland shower curtain with a shade of green that matches the green tile, place green plants around.If no room for plants, use darker green accessories, and leave the floor as is; the black will break up all the green and white. Trim window in green.

I once had a bathroom with chocolate linoleum on the floors. I painted the walls chartreuse green, brought in plants & brown colored bottles. It was beautiful. I took quite a chance on that chartreuse paint, but I found a quart of it at a Sears. It had been mixed and the customer didn't buy it. I guess they lost their nerve!!!

I'd continue the black and white theme. Paint the walls an off-white or even cream, maybe a nice black bathmat, and a white shower curtain.

I think a mid strength grey painted wall would look great. And to bring some colour to the room and to contrast with all the squares I would put up an old ornate oval mirror painted in a dark green. Although a bright yellow would look great, but not sure with the green tiles. Keep it simple and not too busy.

I would do one of two things:

1. match the color of the green tile and paint upper wall, leave trim white and buy a great colorful shower curtain / accessories etc.

2. Tile Decals like this:
http://www.mibo.co.uk/mibo/catalog/product_info.php?cPath=33&products_id=75&oscsid=a2bbabe88834986e7ccbf282a1abbe18

Good luck.

Keep the paint and buy red accessories!

I am so impressed with the responses from everyone! I think we have decided to go with the medium grey paint.We have lots of grey in the rest of our place so I think it ties in the best. I'll keep you posted! Christine

Coral.
It's a deep, rich color. A matching bath mat to tie it in. Don't touch the window frame or mirror.
The bold punch of color on the upper wall and again on the floor will enliven the small space without overpowering it.

Stop with the light gray already! It's only going to make the white whiter, the black blacker and the green greener. I ALWAYS start with fabric, as it gives you a roadmap for choosing everything...and it will all match when you are done. Leave the walls white. Grab two of your 20% off Bed, Bath and Beyond coupons and find a beautiful drape that has some of the green in it, plus lots of white and ANY other colors you like; buy two panels, a white fabric shower curtain liner and a tension rod. Hang drapes on the tension rod and swag them to each side. Buy or make some fun tiebacks. Hang the shower curtain liner on the shower rod. Pick out a color from the drape and use it to accessorize - rugs, towels, etc. Your bathroom will be beautiful and look like a million bucks.

Yellow goes great with black and white tiled baths - and will also go well with the little bit of green tile you have, too.

You can go as vibrant or as subtle on the wall paint color yellow. (Do NOT paint the windowsills black - leave them white, or paint with a paler yellow than the walls.)

You can do a yellow shower curtain, etc, or if that's too much yellow with yellow walls, do either the wall OR the textiles in yellow, but not both (or one in paler yellow than the other.) If you do just the wall yellow, you can pick up the color in the shower curtain in any number of fabric or vinyl shower curtains.

Yellow will look great. I had a black and white tiled bathroom, and when I saw a yellow kitchen in a design magainze with black and white tiles, I knew I'd found the color to decorate by bath, and never regretted it. Towels can be yellow, white, or a green (in the family of the green tile, but not in that green) if you like, or a mixture.

And if you really don't like the green tiles, you could probably cover them over pretty easily with some sort of tile or wall decals (black would look best with your floors, and would go even better with yellow.)

I would hesitate before painting this room gray. The white floor tiles are not as white as the wall tile, and adding gray may only make them look dingy. Adding brown will let the green become a more subtle accent. I would suggest Benjamin Moore Davenport Tan. If you are up for painting the trim, use a creamier shade and not a stark white. Ralph Lauren Architectural Off White is good. I would opt for a neutral shower curtain and add artwork and other accessories for color. The brown will effectively neutralize the green, yet allow you to bring in other accent colors as well-turquoise, yellow, salmon, etc. Just use them sparingly, perhaps only in your artwork.

WALLPAPER!

I have used wallpaper in two bathrooms with great success and NO peeling! The trick is to get it installed well. The English use wallpaper in their bathrooms all the time. You have enough of a tile suuround so water will not get on the wallpaper.

Here are some suggestions from
www.wallpaperdirect.co.uk
a site I use all the time. It shows the samples in various settings. You can get up to 5 samples free. I have bought wallpaper from them with great success. The pound is down at this moment so you can get them reasonably. These usually are available at design centers too if you have one nearby. You don't need much so you can splurge.

Here are some great green wallpapers.

http://www.wallpaperdirect.co.uk/products/brewers/fleur-from-crescendo-by-casadeco/73709

http://www.wallpaperdirect.co.uk/products/brewers/sea-thistle-squid-ink/67798

http://www.wallpaperdirect.co.uk/products/osborne-little/dahlia-trail/25282

http://www.wallpaperdirect.co.uk/products/romo/kimura/42020

Here is the main page of greens.
http://www.wallpaperdirect.co.uk/search-results.php?perpage=12&producttype=both&colour=greens&orderby=&perpage=120

Oops!

I see you have paint inside your shower. Possibly on one wall.

Hi,
My suggestion would be to paint the walls white and decorate with green accessories, staying clear of mint green and not trying to match the green tile. Go for your own favourite shade of green. All greens go together in nature. Try the new Ikea fresh intense grass green towels! Mmmm!

STENCILS!

I feel I blew it earlier-BUT I was going to do this.

Here is a really stunning rather chinoiserie peony stencil- tres sophisticated. You can do it in black on a white wall. Skidou's idea of the towel color is great!

http://www.dresslerstencils.com/product/5576/35