I've been searching for a theme looking like made from neon tubes. Since I found none, I decided to make one myself.
I'm having some trouble getting it to scale properly on startup. Might be due to my machine or to issues of cairo clock, I don't know.
To install just make a folder named ".cairo-clock" (without quotation marks of course ;) in your user directory. In that folder you make another one named "themes" and then you copy the theme folder there. So in the end it's ~/.cairo-clock/themes/real_neon/
I appreciate feedback and suggestions.