Canon 10D User Guide (en)

Brightness of an image can be adjusted. Move the slider to the right to 
make an image brighter and to the left to make an image darker.
Adjusting Brightness
Reverts the image to 
the original settings
Enter a numerical value
Drag the slider left or right
The adjustment range is –2.0 to +2.0 (in 0.01-stop increments when 
entering a value).
If the image you shot is different to what you visualized, you can change 
the Picture Style to get closer to what you envisaged.
Even if you select [Monochrome] and have saved 
 the image, you 
can always revert to a color image by selecting a Picture Style other 
than [Monochrome].
Changing a Picture Style
Reverts the image to 
the original settings
In DPP, even if you change the Picture Style, the [Contrast], [Color tone], 
[Color saturation] and [Sharpness] settings do not change. Change 
each one individually.
Change [Contrast], [Color tone], [Color saturation] and 
[Sharpness] individually
Even if the RAW image is from a camera that does not have 
Picture Style settings, you can still set a Picture Style as long as 
the RAW image is compatible with DPP 
[Contrast], [Color tone], [Color saturation] and [Sharpness] set for 
each Picture Style item can be memorized for each image