I don't buy that this trick would be effective, though I like the sentiment. I would guess that the detail of m&m color could very often be overlooked due to its insignificance and create a false signal.

For one, the same people in charge of safety like riggings and electrical are not going to be the same people that are supplying the refreshments.

I can also imagine a high number of people like myself reading that part and think it's a joke or purposely ignoring it because there are much more important issues to deal with and because I'm not much into indulging the ridiculous whims of self important people.