Clean Cut Metal Works

That's certainly one way to make a rainbow permanent.

This series of photographs of gorgeous welds (rainbows caused by layers of oxidation) was attributed to the same metal artist who makes sculptures are Clean Cut Metal Works.

I'm skeptical because none of the work on CCMW looks anything like the photos above (gorgeous thought they may be in their own rights. Admittedly, I have zero experience trying to weld anything together (though I've done some very basic soldering).

If anything, those above look more like the ones on TheFabricator website.