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I use the inverted colors mode a lot, however after installing ubuntu 12.10 it doesn't work for me any more. The command:

xcalib -i -a


Error - unsupported ramp size 0

I have no clue where to start looking to fix this problem. Couldn't find anything about this error. Any ideas?

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up vote 3 down vote accepted

The gamma ramp is not defined (0), but xcalib expects multiples of 16. Installing gcm solved the issue for me:

sudo apt-get install gnome-color-manager
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Doesn't work for me. Please explain this method, how have you figured out to install gcm? Maybe I find a similar solution for me. I'm using xfce. Inverting works on 3 different monitors, including the notebook's, but doesn't work on a fourth monitor (Samsung S23B350). – Vasya Novikov Oct 24 '13 at 6:55

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