change faces interactively

[ishi soichi]

I'm trying to develop an interactive function that changes faces.

For example, one way to change the face is 

(define-generic-mode my-mode

  nil nil

  '(("think?\\w*\\|thought" . 'org-warning))  ;;changes face of "think", "thinks", and "thought"

  nil nil)

But this changes the face according to the mode, not the interactive command input.

Is there anyway to develop an interactive function like that ?

(defun change-face-to-one ()

  (interactive)

  ...

    )

Thanks in advance.

soichi