When it comes to image quality, faithful colour reproduction is also important. The current state of the art is the display of 16.7 million colour shades, which corresponds to a colour depth of 24 bits. All small portable projectors show slight deviations in colour reproduction due to their technology. You therefore can't expect colour accuracy like that of a reference monitor.
The reference value used is the colour temperature in kelvin, a measure of the colour of light. Daylight has a colour temperature of 6500 kelvin, while the lamps used in projectors usually have higher values. This makes their light bluish and harsh.
You should calibrate a projector's colour reproduction manually, as the factory settings can lead to colour deviations. Calibration eliminates errors in the image.
Deviations also arise from the technology used in the imaging unit.
Cheap polysilicon devices tend towards oversaturated "candy colours" and deviations from the white point. These are most evident as a departure from neutral grey.
Devices with DLP mirror technology always show a neutral grey. However, there are some deviations in the red tones, which are produced by the colour wheel filters.
