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》

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

Behind is the bright blue and light of a cloud-scudded sky.

湛蓝色的天空飘着片片白云。

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

But a clear, cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more easily than they do red light.

BBC: rainbow