I prefer to set Background compile to 'Red inversion'. It's not destracting as underline but gives a clue when somethins is incorrect in the line typed.

>When I type, the text is underlined. Looks like a hyperlink.
>
>If it's a hyperlink - why? Why would you need your code hyperlinked.
>
>If it's not a hyperlink, then what is it (besides annoying).
>
>How do I turn it off?