As long as you simply pass, the health code will not change color, and only when you stay in a moderately dangerous area for a period of time will the health code change color. Health codes are based on real data, and citizens or employees who come back from rework can report these data online.
The results are different with different residence time. For high-risk cities, it will not change color within 4 hours. Driving through high-risk cities, you can get there soon. We don't need to modify the code within 4 hours.