Airthings monitors indicate good/fair and bad air quality with a light color.
GREEN: All sensors indicate good air quality 😀
YELLOW: One or more sensors indicate fair air quality 😐
RED: One or more sensors indicate poor air quality 😣
Temperature does not affect the color of the light
Simply move your hand in front of the device and the ring lights up with the corresponding color.
You can review the recommended thresholds for each sensor here.