Don't mix plumbing fixture finishes in the same room. In fact, don't mix them in the whole house.

We love the idea of mixing metals.

Mix away within limits.

The rule seems to be no more than three metal finishes per room and sufficient contrast to emphasize the mixing is not an an oversight. (Or poor sight.)

OTOH, one client insisted that all their bathrooms were to have the same fixtures and fittings without variation at all. They weren't fond of my comment that such a design resembled a rest stop on an interstate. (Or more accurately, a typical tract home. A tiling contractor once confessed to me how happy for the work but absolutely bored he was with a contract he had for more than 100 townhomes, all with absolutely the same tiles.)

I have even mixed fittings in a single bathroom. For instance, all chrome but a different manufacturer's take on the style in the bathtub than on the vanities. This also helps to "age" the home.

Mixing just has to be tasteful. Even older homes would use a different finish in the formal rooms than the casual rooms. I wouldn't use 5 or 6 different metals in the same room but I don't think there is anything inherently wrong with using a few. Part of it comes down also to the relative style of each of the fixtures. If one is very modern, the other might be in a different finish but also very modern. Just comes down to creating cohesiveness between the various elements.

I have different finishes in different baths/kitchen, but not only in the kitchen have I mixed metals. A bath is just too small to do this.

I take askance at the comment on same fixtures in different bathrooms. I put Brizo matte black in all my bathrooms. It does not look like a tract home OR an interstate restroom. No one is ever in the same room at the same time. And while some like mixed metals, we do not.

It's o.k. to mix metals, as well as not to mix metals :) And the important thing is to like your choices.

I love mixed metals in the same room. Everything all the same looks too "fixed".

I think it's up to an individual person's tastes. Sometimes it works, somtimes it doesn't, and obviously beauty is in the eye of the beholder. For instance the top powderroom with the gold sconces, mirror-framed mirror, the two tones in the vanity and the small plant stand, as well as the varied tile patterns is just absolutely overwhelming to me.

I could handle it with the tile and a white vanity and a chrome faucet and that would be it!

So really is all up to personal tastes, and none are wrong even though they might not be exactly what you or I would choose.

No one is ever in the same room at the same time.

A couple of high end homes I inspected exemplified that thought. One was a swank condominium, every room spectacularly furnished and designed--each in a different style. The owner explained he used the apartment as showrooms for his high-end home furnishings business. The other home had a more permanent display: each of the four baths was the epitome of an era--from Victorian to modern and would embarrass any chichi bath emporium.

There are public washrooms.

And public washrooms.

No one is ever in the same room at the same time.

Yogi Berra is alive and well.

Awesome! Thank you all for the feedback. Here is a photo of the pieces I was planning on mixing. I feel like b/c they are both rustic/industrial rustic that they blend. With the "ORB" being more of a copper with an oil rub effect, I feel like it complements the matte black. I would NOT mix their black and Venetian bronze tones... they are too close together and would definitely look like an oversight.

(Also, I will be changing the drawer pulls on both vanities to better fit the style of all the metal fixtures.)

I think you can get away with mixing those two finishes, especially if you continue using copper and black intermixed throughout the bathroom with lighting, wall mounted and counter top accessories. As you said the near misses are the ones to really avoid.