Red, yellow, green: Test, test, test

When the Health Code was in use in China, the local governments of Shenzhen and Changsha, like many others, required individuals to present a 'green code' to move within and between locations. In this essay, we focus on moments when green codes unexpectedly turned yellow. By studying these changes, we gain insight into how the infrastructure of automated control was challenged when people affected by the system and those administering it had to find ways of working around, altering, or re-enforcing the code.