> I don't think so.  For example here on Windows XP, emacs -Q with current
> trunk, evaluating
>
> (progn
>    (custom-set-faces
>     '(mode-line ((t (:background "#000040" :foreground "wheat" :box (:line-width 2 :color "#000040") :weight bold :family "Verdana"))))
>     '(mode-line-inactive ((t (:inherit mode-line :background "grey48" :foreground "wheat" :box (:line-width 2 :color "#000040"))))))
>    (setq calendar-week-start-day 1)
>    (calendar))
>
> gives screenshot calendar-1.png while evaluating
>
> (progn
>    (custom-set-faces
>     '(mode-line ((t (:background "#000040" :foreground "wheat" :box (:line-width 2 :color "#000040") :weight bold :family "Verdana"))))
>     '(mode-line-inactive ((t (:inherit mode-line :background "grey48" :foreground "wheat" :box (:line-width 2 :color "#000040"))))))
>    (setq calendar-week-start-day 1)
>    (sit-for 0)
>    (calendar))
>
> gives the expected screenshot calendar-2.png.

Sorry.  The screenshots were from an earlier experiment.  The current ones
should fit the description above.

martin