Microtek ScanMaker IIG User Manual page 191

Pixel-value information is useful especially if you are making
color corrections based on color values. Knowing this, you
can modify the shadow and highlight points of an image, then
come back to the same point in the image, and verify through
the Color Meter Display that the RGB values have indeed
changed.
The Color Meter Display can also be used in conjunction with
the Color Picker tool. For more details, see the Color Picker
topic in the Preview Window section of the Reference.
Reference: The Information Window 5-83