Yes, no, maybe. Context is key. Pictures would help us help you.

Taj Mahal quartzite is a natural stone and comes in a range of colors with some a warm off-white & beige, some mostly beige, and some in a taupe-gray-with maybe a hint of green. Some are swirly, which are harder to find these days, and some are stripped.

Hopefully you have a few spare Travertine tiles you can take to the slab yard. Also make sure you look at the slab you are considering outside in daylight, with your tile sample.

Use a porcelain tile in your shower and not stone.

Becareful with polished materials on shower floors. May be unsafe.

I have Mont Blanc stone (similar to Taj) on the curb top, shower trim, and countertop with an Ann Sacks travertine-looking porcelain tile on the shower walls -- the colors are close enough to be almost indistinguishable.

Have you considerecd a large-format (24"x48") porcelain tile instead of slabs for the shower walls and the bathroom floor?

Yes, polished light travertine and Taj Mahal can work together, but I would judge the combination by undertone and surface behavior, not by material name alone. If your existing floor reads soft cream and the Taj slab stays in that same warm family, the pairing can feel calm and layered rather than busy.

For the shower, I would separate the style question from the performance question. If the goal is to avoid future pitting, dark spotting, and maintenance around pores, a good porcelain wall tile that captures the travertine look is usually the safer long-term move than repeating natural stone inside the shower.

I work with a lighting and metal hardware manufacturer, so I look at this from a production and QC perspective. Since you are keeping white cabinetry and champagne bronze hardware, I would make sure the shower wall, countertop, and metal finish all stay in one temperature range so the room feels intentional instead of slightly mixed.

yes absolutely agree on the flooring. Was planning on a pebbled type flooring. What are the issues with Taj Mahal as a shower stone, just curious. The quartz/granite/porcelain seller said Taj Mahal would be fine.