Turn The Root Shell Prompt Red in Linux
Linux newbs are usually scared of the terminal, it’s commands are nonsensical to them, and they’re afraid of doing something wrong, especially if they have to work as the root user. Some of them might not even be sure if they’re in the root account or not, which is why this hack is so useful. By adding two lines of code to our /root/.bashrc file, you can easily distinguish which account you’re using. When you’re working as root, the prompt will turn red, and when you’re not, it turns green:

Just add these two lines to the end of the ~/.bashrc file:
PS1=’${debian_chroot:+($debian_chroot)}\[33[01;31m\]\u@\h\[33[00m\]:\[33[01;34m\]\w\[33[00m\]\$ ‘
And:
PS1=’${debian_chroot:+($debian_chroot)}\[33[01;32m\]\u@\h\[33[00m\]:\[33[01;34m\]\w\[33[00m\]\$ ‘
[via Lifehacker]