Does antimatter appear the same as matter to the naked eye?

It appears the same.

Exactly the same.

You see, by the rules of "anti", a photon is its own antiparticle.

(It seems, also, that neutrinos could be the same case, but we are not completely 100% sure yet).

Thus, when an anti-electron, in orbit around an anti-proton (in an anti-hydrogen anti-atom) drops from an excited orbit to a less excited orbit, it emits a photon of EXACTLY the same energy as if an electron, in orbit around a proton, had made the same orbital drop.

Same amount of energy = same photon (same wavelength, same frequency, same everything).

Anti-matter has the same electromagnetic properties as normal matter does, making it impossible to determine by observation at a distance the matter state. Likewise, anti-matter behaves in a complementary manner chemically with itself. Only in contact between normal and anti-matter would there be a difference. The resultant annihilation is so catastrophic that the presence of both in the same place is obvious and routinely seen in cyclotron experiments.

Quantum theory postulates that the universe is equally matter and anti-matter. One supposes that previous annihilations into energy would create space between them. Anti-matter is routinely made in the lab by converting the energy of collisions into mass. But storage of any significant amounts hasn't been accomplished.

No, they appear different, but clearly not to the unclothed eye. One can't see them or their straight twins with the naked eye.

But to a point. When using detection devices, we know the anti matter from the matter simply because they do appear different in some property. The positron, for example, appears to swing to the negative plate rather than the positive one. That shows the particle has a plus rather than negative charge.

I doubt you can create anti-objects. Certainly live objects would not be viable as the electro-chemical process of life would be all wrong with anti mass. And I really can't envision anti quarks forming anti nuclei surrounded by positrons. And anti photons coupling with those positrons staggers the imagination.

Nope...don't see it.

"My question is, does antimatter create duplicate spectra?"

Excellent question. Our current theories say yes. We don't have any experimental data yet to answer this question. CERN has a project in progress to experimentally measure this very thing.

I should think to a human made of antimatter, the antiphotons would have the same wavelengths and asppearance as there is no reason to suppose the contrary.

"Raymond" has an excellent answer:

http://newscenter.lbl.gov/feature-stories/2012/03/...