The U. E. gray in some of the photos of me wearing it seems to have a bluish cast, but that's because of light from the bright, blue sky.

E 灰在一些我的着装照片中好像有一层蓝膜，而这是来自晴朗的碧空的光线， U。

youdao

Mongolian spots (technically named congenital dermal melanocytosis) are flat bluish-green, gray or light brown areas where cells called melanocytes have been trapped in a layer of the skin called the dermis.

CNN: What are Mongolian spots?