Entering Unicode Characters with `ssh … tmux -CC a -t theSession` on iTerm2

Not as part of the iTerm 2 configuration. iTerm has no way of knowing you've gone to root in a remote session -- it's not watching what you're doing that closely (and what you're asking it to figure out is actually really complicated to program).

You can create an iTerm profile that has red text on whatever background colour you want and you always use that profile when you're going to go to root on a machine. It requires no changes to the root environment on the remote machine. But it does require you remember to use that profile for your rooted session.

Edit: while digging around I found this interesting article that talks about how you can change the background image in iTerm to show the hostname of the host you've ssh'ed in to. Notice how it's all based around the environment in your client's Mac shell -- once you're on the remote machine there's not a lot iTerm can do. The changing of a tab title does appear to be controlled by $PROMPT_COMMAND, as set in the remote session's environment, but there appear to be no documented hooks in iTerm 2 that let you extend what iTerm does when it changes the tab title. Pity.

I tell ya: mad props if anyone can figure out how to do this. It'd be handy for sure.

ls output with colors (ls -G) is not the default option. Run the following command in your terminal to enable ls colors by default:

echo "alias ls='ls -G'" >> ~/.bashrc
source ~/.bashrc

This and all future terminal sessions will now display colors correctly.

If you're still not seeing colors on your remote (or local) session follow these steps:

In iTerm verify that you're sending a terminal type that supports colors. Open the preferences window -> Profiles -> Default -> Terminal. I'd recommend putting xterm-256color as the Terminal Type.

While connected to the remote machine, run ls -G and open the iTerm preferences again: preferences window -> profiles -> Default -> Colors. Adjust the ANSI Colors, and turn the minimum contrast down until the colors in the terminal window start to show color.

If the remote system supports ls --color=always, remove any existing aliases in ~/.profile or ~/.bashrc and update as follows:

echo "alias ls='ls --color=always'" >> ~/.bashrc