(defface django_tags '((t (:background "tan3"))))
;; (defface django_variables '((t (:foreground "purple"))))

(font-lock-add-keywords 'html-helper-mode
 '(("\\({% .*? %}\\)" 1 'django_tags t)))

;; Original test line that worked: '(("\\<\\(FIXME\\):" 1 font-lock-warning-face t)