When in Lisp mode, the LispWorks editor provides automatic Lisp syntax coloring and parenthesis matching to assist the editing of Lisp programs.
You can ensure a buffer is in Lisp mode as described in Automatic entry into lisp mode.
To modify the colors used in Lisp mode syntax coloring, use Preferences... > Environment > Styles > Colors And Attributes as described in the LispWorks IDE User Guide . Adjust the settings for the styles whose names begin with "Lisp".