I would color a bar, shield it with probably aluminum sheet on each end, and then expose the bar to high levels of narrow spectrum uv light until summers end. Pick your nanometer.
There is a continuous conflict between people that have observed fresh case coloring (without clear(ish) coatings) degrading in short periods of time, and those that say the surfaces are inert to light.
I suppose the bar could be laid in a tupperware box filled with argon or tri-mix to exclude oxygen.
I do not believe ferro-oxygen coatings are inert in our atmosphere. I believe there are great numbers of compounds captured in the films at quench, and some are very delicate. Delicate merely implying they can be changed in conformation or presence via outside energy, within the realm of what we might normally provide.
I worked in inorganic polymers during the cold war in an effort to protect carbon forms from neutrons. Even in the most extreme conditions, we had isomers, conforms, and stability issues.
I'm kinda glad it didn't work out, because ultimately it supported the limited use of atomic weaponry.
We should use this WWW of interested parties to cooperatively demonstrate, and collect these pieces like Drew and Pete have done for Damascus barrels.
Lots of deceased scientists findings have been refined and enhanced after their passing.
I used to have to re-do every experiment that came from a Russian publication. Even if it was re-heating H2O.(joke)
