Dell 5110cn Color Laser Printer - Manual (Page 381)

Specifies RGB Color Correction.
Available RGB Color Corrections are as follows.
0
Off
1
Photo
2
sRGB
3
Standard/ Normal
4
Presentation
This option is available only for color printing.
-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
-Sc=mode