From: Piotr Gasiorowski
> Note that *s^e^rU (as in Pol. szary) is geographically restricted inSorry, a blunder on my part. Of course it's all consistent with *s' from
> Slavic and may well be nothing else that Gmc. *xaira-. The rest of
> Slavic has *se^rU, which is a regular reflex of *k^oiro- ...