This. Van Halen has stated as much - if there are brown M&Ms, chances are really high they haven't paid attention to detail, and a deep dive is going to uncover some serious problems:

https://www.smithsonianmag.com/arts-culture/why-did-van-hale...

As an aside, I did think the M&Ms story was just a band being a diva until I heard them explain it like this. It's actually brilliant.