Why can't a static health card be black and white?

Static health cards can't be black and white, because black and white colors can't tell what risk area you are in. According to the relevant public information displayed by the query, the health status can be judged according to the color of the health card, and the health status cannot be distinguished from black and white. Health cards are based on real data and can be generated by citizens or people returning to work through online declaration and background audit.