If the health code is green in other places, the risk level is low, and if the risk level of the destination is low, it will generally not change color. However, if you contact an infected person on your way back, the health code may change after you go back.
If your area is a low-risk area, punch in the national government affairs platform every day 14 days before going out, and the health code is green. Going to other areas outside the province is also a low-risk area, and it will not change color, or it will be green.