Chesterton's Fence [0] should overrule fear of cargo culting, especially when the fence (or in this case color) was clearly put up by people who really knew what they were doing at the time.
Unless there is a significant cost to it, and unless the benefit is understood, there is no reason that they should be faulted as ignorant cargo cultists simply for keeping it in place.
> For decades, Intel’s cleanrooms have been lit like darkrooms, bathed in a deep, low yellow. “That’s an anachronism,” says Mark Bohr, a small, serious man who has spent his entire 38-year career making chips, and who’s now Intel’s top manufacturing scientist. “Nobody’s had the courage to change it.”
It's possible that some level of unresolved empirical "magic" be involved in the process, which does not diminish the value of the end product. Why deprive yourself of hard learned lessons even if you don't understand it all?
Unless there is a significant cost to it, and unless the benefit is understood, there is no reason that they should be faulted as ignorant cargo cultists simply for keeping it in place.
[0] https://www.chesterton.org/taking-a-fence-down/