Thats not very good advice
Even though it was a joke, it was actually really, really bad advice. It may look cool, but if you wear your cage flapping about it will kill your vision. The motion will distract your brain and make you focus on your cage. The white will make it harder to see the cage so there's less of an impact from that, but you'll still be noticing the cage and not the play.
However, if you wear your cage properly, it stays in the same place in relation to your eyes, so your brain will just look right past it and you'll have no problems.
Also, black absorbs light and is less likely to stand out to your brain in relation to a play, chrome blends in to the surroundings, and white disguises itself in relation to the ice. All have theories behind them, and I don't know if anyone's done any testing. I do know that some arenas have done testing for netting and have found that it's easier for an audience to look past a black net then it is for a white one.
But really, it doesn't matter if your brain can just look past it. And your best bet for that is wearing the damn thing properly.
For the record, I wear a black cage and don't notice any change in vision from when I'm screwing around after a shift at the rink without a helmet at all.