lighten

The manager tried to lighten the mood by telling a funny story.

(Chinese) 经理试着讲一个有趣的故事来缓和气氛。

Her face began to lighten as soon as she heard the good news.

(Chinese) 一听到那个好消息，她的表情就开始变得轻松起来。

You can add a bit of white paint to lighten the blue for the sky.

(Chinese) 你可以加一点白漆，把用来画天空的蓝色调浅一点。

The sunrise began to lighten the dark clouds over the mountains.

(Chinese) 日出开始照亮山顶上空的乌云。