The blue of the sky paled to a light grey.

天空的蓝色渐变成了浅灰色。

《牛津词典》

That's because the ambient light (in this case the blue sky) gets bounced of pretty much everywhere specially the Shadows.

那是因为环境光(蓝色的天光)被更多的反弹，尤其在阴影的部分。

youdao

The color is magnificent, with the cobalt blue sky in the background and the warm light on the lion.

背景中钴蓝色的天空和狮子身上暖色调的光线，颜色好极了。

youdao

Already the moon had risen, a flake of waxy alabaster in a blue sky thin with light.

NEWYORKER: She��s the One

As if to spite me, the sky was blue, and the light was too brilliant.

NEWYORKER: The Slows

Comprised of a surface pattern of triangles-like those in the main theater, but made in this case out of 1, 067 thin aluminum panels, mounted on the support structure with open joints-the light-blue facade looks razor-sharp but creates the impression of a super-light floating skin dematerialized against the sky: another visual reference in the architecture to the infinite thinness of the moving image.

ENGADGET: Museum of The Moving Image plans multi-million dollar updates with HD, 3D