Have you tried Subway Ceramics? They've got what they promote as an authentic vintage white color called 'Avalon' for their absolutely flat rectified tiles that fit with old ones. Alternatively they also offer a bunch of period colors so at least you'd have the correct flat profile for your add-on portions. Might give them a holler/order a sample?

If you can afford it, I'd recommend replacing the tile on that one wall, but not the whole room, if possible, so that the repair isn't as obvious.

Here is a link that might be useful: Subway Ceramics

You could separate the old tile at the 4 ft level from the new tile with a border tile in a vintage pattern, then use new tile (perhaps from the co. circuspeanut recommends) above the border in a complementary color/pattern. I think all black might be too much, but you could incorporate black in your pattern. You also might get some good ideas on the bathrooms forum. There are some tile gurus over on that side and some people with beautifully done baths in vintage homes. Check it out.

If you can't match it's often the best thing to go with a total contrast: colour, shape, gloss. Profiled trim pieces can help to make the dividing line a feature, kind of like a chair rail in tile.

You could post a picture to generate some ideas.

KarinL

I don't think I'd go with black, but if I did, I'd probably try a different shape than the subway.

I think I'd put a border/pencil liner/chair rail above the old tile then go up with wall with a complementary color in a different pattern and shape - like 4 or 6 inch tiles laid in a diamond pattern. I think you could probably even go with the best white match you could find, since it wouldn't abut the subway tiles and would obviously be a different tile.

Euc

You could try the link below - for tile that matches

I would not do all black - unless you really want a "man cave" - + depending on your water mineral deposits, soap scum etc will be constantly hazing the black tile imo

good luck

Here is a link that might be useful: resoration tile

Our friends did this. They have a peach colored tile, with black trim. They replaced plumbing in their bathtub, so the patch of wall where the faucets are got black tiles. It doesn't look bad. Ours was replaced with white on white, new on old, and you are right, you cannot match the old subway tile. The closest match I could find was at Lowes. I brought several whites home, and viewed them in different lighting - day and night - to see what worked best.

If I were you, since I've seen it done both ways, is I'd go black since it will coordinate better than two different whites.

Replacing the original tile, if your home is older, is probably going to be a huge undertaking as it is probably set in concrete. Ours has a concrete in metal mesh type backing. Had to be removed with a sledge hammer.

Good luck.

We had a similar thing in one of the bathrooms in our old house. While I'm sure this is TOTALLY not recommended - since we only use this bathroom about 2x per week, we just installed a shower curtain, did heavy caulking and used a waterproof paint, rather than re-tile the whole bathroom.

We were warned the plaster could get damaged, but we thought, well, if it is damaged, then we will spend the money to have the proper waterproofing and tile done.

Six months later, so far, so good..... And it kept the original tile which we love and is beautiful.