Dell 3115cn Color Laser Printer User Manual page 576

Specifies image types.
Available image types are as follows:
0
Off
1
Photo
2
sRGB
3
Standard/ Normal
4
Presentation
This option is available only for color printing and when entry data is RGB data.
-Gc=mode
Specifies RGB gamma correction.
Available RGB gamma corrections are as follows:
1.0
1.0
1.4
1.4
1.8
1.8
2.2
2.2
2.6
2.6
off
Off
This option is available only for color printing and when entry data is RGB data.