In one of 宮沢賢治's stories, the following sentence appears:
そのとき風がどうと吹いて来て教室のガラス戸はみんながたがた鳴り、 学校のうしろの山の萱や栗の木はみんな変に青じろくなってゆれ、 教室のなかのこどもはなんだかにやっとわらってすこしうごいたようでした
My question is as to what the meaning of 青じろく (青白く) is here.
The technical definition of this word seems to be "bluish white" or "pale", however in context I don't understand why the trees "paled strangely".
Are the trees "paling" because their leaves are turning over due to the wind? Or for some other reason?
Or would "darken" be a closer English word to express this usage?