Is there a way to turn on indicator that a directory item is a shell script in Terminal?
Try typing ls -G in terminal, you should see colored listings by file type.  If the scripts aren't being shown in a different color, this means that they are not marked as executable, so you will need to type sudo chmod +x &lt;filename&gt; to make them so.  Then they should appear in a different color as opposed to directorys etc.

If you prefer not to always type ls -G then you can put the following command in your .bashrc file in your home directory  alias "ls"="ls -G"  Then restart terminal and you should see colored output whenever you just type ls