Name: xcalib
summary : Tiny monitor calibration loader for X.org
Version: 0.8
OSS: Yes (GPL2)
URL: http://xcalib.sourceforge.net/
SRC: http://downloads.sourceforge.net/xcalib/xcalib-source-0.8.tar.gz
Sha256sum: 8a112ee710e5446f6c36e62345b2066f10639d500259db8c48bf1716caea06e6

It is a useful utility to change brightness, and invert colors. Thanks.

Example usage:
xcalib -a -i ; #invert colors

xcalib -a -co 80 ; # brightness 80% good for reading or when screen is too bright; or when physical button is damaged

xcalib -c ; # reset to defaults (clears invert or brightness etc.)

Thanks.