god-mode color

[BP]

Hi everyone!

I'm trying to make some cosmetic changes of my emacs depending on god-mode 
state. For now I have this :

(defun my-update-color ()
  (setq cursor-type (if (or god-local-mode buffer-read-only)
                        'box
                      'bar))
  (set-cursor-color (if (or god-local-mode buffer-read-only)
                        "firebrick1"
                      "LawnGreen"))
  (set-face-background 'mode-line (if (or god-local-mode buffer-read-only)
                        "red4"
                      "DarkCyan")))

(add-hook 'god-mode-enabled-hook 'my-update-color)
(add-hook 'god-mode-disabled-hook 'my-update-color)

However my-update-color is not called when I switch to another buffer and the 
appearance of emacs remains unchanged whatever the state of god-mode in the new 
buffer.

Does anyone have an idea to make the color update correctly?

Thanks,

BP