betray too green an interest

What a man thinks of himself, that it is which determ- ines, or rather indicates, his fate. Self-emancipation even in the West In- dian provinces of the fancy and imagination—what Wilberforce is there to bring that about? Think, also, of the ladies of the land weaving toilet cushions against the last day, not to betray too green an interest in their fates! As if you could kill time without injuring eternity.

I know this sentence means that the women do not care about their fates by reading the translation. However, could you tell me what does the word "green" mean in the phrase "betray green an interest in"?