Canon PowerShot SD870IS User Manual page 121

Various Shooting Methods 1119
_] • The default setting for color swap mode changes green into white.
• You may not obtain the expected results if you use the flash.
• The colors specified in the color swap mode and the color
range are retained even if the camera's power is turned off.
• The ISO speed may increase, or the noise in the image may
increase depending on the shooting conditions.