pic in Tim McLelland’s book on the Lightning (p78)

There is indeed. I didn’t find much information about the markings other than the much-repeated belief that they were applied for the air show. I have my doubts though as it would seem a tad pointless. I suspect the markings were actually applied for an ACM exercise and were simply still there when the air show came around. The WS10 markings though are far simpler to explain – they’re simply zaps as has been said. I assume the reference regarding decals must mean these markings as I’ve never seen any evidence of anything more spectacular in terms of German markings on Lightnings – much as I’d like to!