How do I make, find or install Themes? (colours)

[DetectiveMittens]

How do I make, find or install colours themes?
The + button under the build-in themes wants me to browse to a .zip but I can't find any theme.zip's out there on the internet.
I would be keen to make a set of custom colours myself

[theotheroracle]

https://github.com/commetchat/commet/wiki/Custom-Themes

[zeyus]

I made a discussion thread here where people might like to add their own custom themes to?
#874