Final answer:
Wearing a green hat in Taiwan symbolizes infidelity and indicates that a person's spouse might be cheating, which is a cultural belief deeply ingrained in Chinese and Taiwanese society.
Step-by-step explanation:
In Taiwan, wearing a green hat has a specific cultural significance. It is associated with infidelity and implies that someone's spouse may be unfaithful. The phrase comes from the Chinese idiom "to wear a green hat" (戴綠帽子), which signifies that a man's wife is cheating on him. This connotation is deeply embedded in Chinese culture and the related Taiwanese society, making the act of wearing a green hat in public a social taboo.