Brightness
You can choose one of seven brightness levels for scanning. Medium is the normal setting.
It is better to use darker settings for line art or faint original images, and to use lighter settings for darker original images. The brightness can be combined with any other function.
The graph below shows the differences between the brightness settings when the gamma correction is set for the CRT Display A setting.
Lightest setting
Normal (center)
Lighter
Darkest setting
Data output
Darker 
Lighter
Image input
Color Mode
The color mode specifies color reading or monochrome reading. In color reading, you can choose either page sequence reading or line sequence reading. In monochrome reading, you can specify a dropout color (green, red, or blue).
Expression 636 Scanner Settings