It will not change color under normal circumstances. "Hangzhou Health Code" is a measure to strengthen the prevention and control of epidemic situation in COVID-19 by using big data figures. Its three-color code judgment is dynamically changed based on the update of big data in the background of the system.
If it really changes color, there are two ways:
① Health codes may change color after passing through high-risk areas. If the health code changes color, you can click on the "online complaint platform" next to the health code to make a complaint, and the staff will review and judge as soon as possible.