This is because blue was related to rain, or storms, and in Greek mythology, the god Zeus would make rain when he was sad (crying), and a storm when he was angry.

因为蓝色与雨或暴风雨有关，在希腊神话中，宙斯在伤心时会降雨，生气时会有暴风雨。

youdao

And the movie is so sad that you can't stop from crying really loudly

这部电影太令人感伤了，你控制不住地哭出声来。

I can't help but 课堂 - SpeakingMax英语口语达人

"It's really hard, you know there are lots of people in there crying now, it's such a sad time, " he said.

BBC: Candlelit vigil for Jamie Heaton