It's time to come out, but it hasn't been tested, so it will be blank. Generally, this kind of situation will come out as long as you wait a little longer. Ok, don't worry, wait a minute. If the printed health code has no color, it may be that you have no color printing. Generally speaking, only health codes printed in color will have color. According to national requirements, old people or children can add peers without using mobile phones. If the elderly need to go out alone, you can also print the health code for him or issue a certificate for his community. Paper health codes are valid for seven days.