[beezdotcom]

No, I think they would effectively be black since color is relected light at various wavelenghts and black is the absence of color.

This stuff doesn't absorb - it is incredibly transparent (which is why it doesn't reflect). Therefore, they will look like they are covered with nothing.

[conservatism_IS_compassion]

You and I were, perhaps, both wrong. The first application of the material was as you discussed - but at the end of the article we see:

• Black body radiation. The development could also advance fundamental science. A material that reflects no light is known as an ideal "black body." No such material has been available to scientists, until now. Researchers could use an ideal black body to shed light on quantum mechanics, the much-touted theory from physics that explains the inherent "weirdness" of the atomic realm.

Maybe the answer is, (e) all of the above.

Maybe you make your lens coating out of this stuff, and the lens appears perfectly black because there is no possibility of light coming out once it goes in. Therefore it perfectly cloaks anything behind it.

If you were in a bubble of this stuff, you could see out perfectly (because it lets radiation in, but the bubble would appear perfectly black because light could not come out. The perfect thing to put behind a one-way mirror.

[Jedi Master Pikachu]

The article, here, states that if the material is on a clear thing, it will be clear, but if on an opaque substance, it will look black.