How Do I Adjust "White Balance Shift" in Movie Mode (T3i)?

In still picture mode the Menu of the T3i camera allows one to select "WB Shift/BKT" to adjust the amount of Green, Blue, etc., in my photos, but "WB Shift/BKT" is not available in Movie mode. So how can I get rid of unwanted yellowish-orange colortones in my videos of landscapes and replace them with the more natural looking bluish-green tones?

Thanks (I'm still a beginner).

I don't have a T3i. My 7D does reflect white balance shifts in movie mode. Try setting an extreme shift in still mode and see if it shows when recording a movie. According to the manual (page 147), white balance adjustments are supposed to be visible in movie mode.