In it were some old things—a bright blue feather, a tiny V-shape leaf and some dolls.

里面装的是一些旧东西——一根亮蓝色的羽毛，一片小小的 V 形叶子和一些娃娃。

youdao

There's something special in a blue feather.

蓝色的羽毛有一些特别。

youdao

But blue feathers result from refraction, a prism-style splitting of light inside a feather.

但是蓝色羽毛是靠折射光形成的，那是羽毛中一些类似棱镜的结构将蓝色光分离了出来。

youdao

She's a botanist, and she was wearing a feather in her hair, a cerulean blue feather, in honor of the occasion.

WSJ: Of Feathers, Showgirls and Biology