Question: Is there a way for the command line and the output to be in different colors? For example, I've been playing with the PS1 value so my prompt is in red, but I'd like to have the command line in green and the output in white (ex: if I type "ls", that's in green, and then the file list is in white).

Answer: 
You need to have the shell, or a program, emit the appropriate escape sequence to change the colours after you press enter.

The bash shell used by current OS X doesn't have an obvious facility for doing this.
You could bind another key to send the escape sequence and a return.

1. In Terminal's preferences, click on the Settings pane, then the Keyboard tab.
2. Click the plus button.
3. Choose a modifier and key. Set the action to `send string to shell` and the string to `\033[m\015`. Click OK.

You'll have to get used to using that keyboard shortcut instead of `return`…although there's probably an app that will let you the system treat `return` in Terminal as that alternate shortcut.