Whitebalance Fail

Was playing with the new (to me) Canon 300D this weekend and set a custom white balance for the very yellow 'soft white' CFL bulbs in the living room.  Ambient light shots in the living room came out great.  The dear wife claims my shot of her in the living room looks like a studio shot.  Then I did some other shots, without changing the white balance.

With the on-camera flash:



In the boy's bedroom with his 5000K 'Daylight' CFL lamp for backlighting:



And a gorgeous blue cast fail with the same 'Daylight' CFL for side lighting:



Lessons learned?  You can get cool effects with custom white balance.  Reminds me of the old film days where you'd use tungsten film outdoors, or outdoor film under tungsten lamps.   Also, reset your settings before you change lighting situations.