In China, we use red paper for hongbao because red means good luck.

在中国，我们用红色的纸做红包，因为红色寓意着好运。

youdao

Because red is a color with joyful.

因为红色是开心的象征。

youdao

Wear red clothing because red symbolizes luck.

穿红颜色的衣服或装饰红颜色的物件，因为红象征吉祥好运。

youdao

He also had three sisters. While growing up, he became known as Red Adair because his hair was bright red.

VOA: special.2009.03.22

I wish it didn't say "exit," but it does say "exit," because that kind of weakens my point, but over many auditorium doors a red light just hangs there.

如果这些灯上没有注明出口就好了“,因为这样会削弱我要证明的观点，礼堂的门上一般会挂着一盏红灯。

耶鲁公开课 - 文学理论导论课程节选

In Ruxton's Life in the Far West there's an Indian who gets red all over blushing because he got so many scalps and he runs like hell into the plains to glory over his deeds in hiding.

在《卢克斯顿的生活》里在美国中西部有一个印第安人,他因为得了太多头皮而全身涨得通红,拼命跑到草原里来藏起他的荣誉。

耶鲁公开课 - 1945年后的美国小说课程节选

However, Red Bull's U.S. revenues still outrank Monster's because Red Bull charges more per ounce.

FORBES: Never Say Never

Still, his team has led the complaints to Pirelli because Red Bull uses exhaust gases to improve its cars' rear downforce, which exposes the tires to more heat.

WSJ: Tire Trauma as Formula One Stars Feel Heat

They say this is because the red warning lights aren't visible in fog or low cloud.

BBC: London helicopter crash: What are the rules for pilots?