Brother DCP-8020 - Manual (Page 187)

USING THE WINDOWS ® -BASED BROTHER SMARTUI CONTROL CENTER (FOR WINDOWS ® XP) 10 - 32
3. Select Scan Settings.
You can select the scanner settings from each of the Scan Type
options for the Custom buttons. You have the option to select Color
Mode, Resolution, Paper Size and Brightness and Contrast settings.