lol yeah thats true. alternatively, you could use the same colours by selecting them all and scaling them together, then repeat the process for well.. forever! kinda like placing 2 mirrors opposite each other so the reflection goes on forever. or facing a camera at the tv it's streaming to. trippy huh.
Yeah, that's also a solution. But I think that it'll much more extend rendering time. Becouse even if the last visible cube is 1mmX1mm, it's still there and program has to deal with it. And glass is one of the most complicated materials to render (at least in C4D)