Hey, have you heard of humidity indicator cards?

HIC stands for Humidity Indicator Card.
According to J-STD-033D requirements, HIC should be used in the packaging of moisture-sensitive devices. HIC comes with either 1, 3, 4, or 6 color circles, which are either blue, brown, or yellow. The standard specifies that HIC must have at least 3 circles and indicate humidity values of 5%, 10%, and 60%.
Additionally, the standard states that in an environment of 30%-60% humidity, after taking out the HIC, the color circle that indicates a humidity value of 5% should completely change color within 7 minutes, and the color circle that indicates a humidity value of 10% should completely change color within 10 minutes.