I installed xcalib using:
sudo apt-get install xcalib
Then I could invert color using:
xcalib -i -a
However after I restarted my computer this is not working. Why?
I tried removing xcalib using both:
sudo apt-get remove xcalib
sudo apt-get purge xcalib
and re-installed xcalib.
Still xcalib isn't inverting colors. How do I fix this?
p.s.: My question is different from this as I don't get any error message.