Tmux true color (24-bit RGB) support.
Over the last year or so (2013+) there's been a few terminal applications that have begun to support 24-bit or true color mode. The application I most wanted to take advantage of this was emacs where I use colorized themes (solarized, zenburn, etc). Eventually I found a diff and improved it some and posted about it here.
But normally I run emacs within tmux so I needed support within that as well. I found a mostly functional diff here; however, this didn't support the newer ":" delimiter as well as needing some cosmetic changes to apply cleanly to the latest tmux (1.9a).
Here's the result: tmux-1.9a diff
Happy Colorful Hacking.
Screenshot of emacs in tmux running in iTerm2 with 24-bit color.