Meteorologists use color enhanced imagery as an aid in satellite interpretation. The colors enable them to easily and quickly see features which are of special interest. Usually they look for high clouds or areas with a large amount of water vapor.
In an infrared (IR) image cold clouds are high clouds, so the colors typically highlight the colder regions.
The bar on the right side of the image indicates the pixel brightness values for the corresponding color. The temperature can be determined from the following formulas:
For B > 176
T = 418 - B
or when B <=176
T = 330 - (B/2)
Note that the resulting temperatures are in Kelvin.
For IR data, the highest pixel values correspond to the coldest temperatures.
GOES Eastern US SECTOR Infrared Image