A picture would really help.

Here is the existing shower

What part is leaking? It's so difficult to fix one part of a tiled shower like this, especially if it's an issue with original installation. It might be possible to sawcut the tile outside the shower, and completely redo the shower, installing a tile base and new tile walls. Or maybe use a solid surface material so it's less obvious it's been redone.

Thank you for your response. The base is leaking into the wall and down to the crawl space underneath. I would actually like the redo the whole shower and new tile walls (only in the shower) but was wondering from a design perspective if I can mix tile patterns not to match exactly, but somehow complement the existing tile. For example like a light tan/beige subway tile; would that look strange to mix a more modern look with my older existing look?

How far does the tile go elsewhere in the bathroom? Can you post some more photos?

You could always tear out all the rest of the tile and just repair/paint the drywall instead of tiling it. But again, it depends on where else there's tile.

The tile actually goes around the entire bathroom. That's a good idea, but I'm trying to minimize the remodel to just the shower. I'm open to repainting the walls in the drywall areas...

I'd be inclined to remove all tile, repair drywall, paint and totally new shower.

If the tile goes behind the vanity and backsplash, I am not sure how to handle that.

Have you looked for similar triangles trim tile? Sometimes a contrasting border can minimize the difference of appearances between new and old.

I'd also be inclined to just tear out all the tile and repair drywall. Messy, but not that big of a deal.

But if you're not wanting to go that route, then accept that you won't have an exact match, and find some bullnose tile that coordinates well enough to terminate the wall tile short of the shower in a vertical line.

Thanks for all the input! Is it possible to put new tile right next to the old tile or would that look to drastic of a difference? Where the new tile is maybe a subway tile? I haven't been able to find any pictures of that scenario. What about like this?

I couldn't find an example of solid surface next to tile, but I still think that's an option. As far as tile, I think subway tile will too busy a pattern next to the large format tile. I think I would find a large format tile that is close to the color of one of the trim pieces.

I see. Thanks for the advice! Something closer like this?