There are two kinds of idioms in modern context:
1. New forms and new meanings, such as "autumn rain with tears", "Lin Mao Yang Yin", "Juda soy sauce", "Zhao Shan envies ghosts", "pigs wear lipstick", "one country, two systems", etc;
2. The old form and new meaning (including the rational meaning and the color meaning), such as: "a mere drop in the bucket", "a sincere heart", "living like a year", "knowing books and reaching etiquette", etc.