http://jonls.dk/redshift/
https://github.com/jonls/redshift/releases
# python2
https://github.com/jonls/redshift/releases/download/v1.8/redshift-1.8.tar.bz2
# python3 (won't build on stock slack)
https://github.com/jonls/redshift/releases/download/v1.9/redshift-1.9.tar.xz
https://github.com/jonls/redshift/releases/download/v1.9.1/redshift-1.9.1.tar.xz
https://github.com/jonls/redshift/releases/download/v1.10/redshift-1.10.tar.xz
https://github.com/jonls/redshift/releases/download/v1.11/redshift-1.11.tar.xz