Interesting, did some light (heh) digging.

[1] agrees that World War II-era luminous materials featured radium, yes. Another use seems to have been putting discs on helmet fronts of paratroopers, to help soldiers see each other in the dark.

This page [2] has a picture of a variety of luminous products from the era, and also mentions one civilian usage was marking edges of clothing, also to help make pedestrians more visible in the (blacked-out) streets.

I'm rather low on the Interest in History scale, but it's fascinating how often WW2 manages to deliver something new. Thanks.

[1]: https://www.paratrooper.be/articles/luminous-disks/

[2]: http://www.butterflybalcony.com/2013/10/the-home-front-black...