Manufacturers of digital cameras usually rate their CCD's sensitivity to the equivalent of a film's sensitivity. Hence, if a CCD is rated at ISO 80, this digital camera is as sensitive to light as a normal film rated at ISO 80 is. This gives the photographer more flexibility for action shots or even for low-light situations. Unless you really need to, don't change the ISO setting as it is comparable to pushing a film. If you get strange colour tints, try to calibrate the white balance or change to preset settings to suit the colour temperature of the light source.
Colour temperature measures the colour quality of a light source.
The concept of colour temperature is based on the radiation emitted by a black-body and is very technical and complicated. Digital photography brings a whole new dimension to the area of colour temperature in photography. Previously, in conventional photography, the photographer had to use colour correction filters to correct for the various colour temperatures. There was also the choice of tungsten or daylight-balanced film. For digital photographers, things are less complicated as colour temperature correction is usually automatic.