Illuminance, lamp type and performance on a colour discrimination task

This experiment attempts to validate the advice given in the IES Code concerning lighting requirements for the performance of tasks involving colour judgements. This advice is to use lamps of good Colour Rendering Index to provide a high illuminance. 15 subjects performed a colour discrimination task under four different fluorescent lamps and two different illuminances. The results show that for the lamps commonly used in interiors better, or at least equal, performance is obtained when the task is performed under lamps of good Colour Rendering Index. However illuminance changes over the range 300-1000 lux had no effect. It is concluded that the advice given in the IES Code is partially correct. It was also found that neither Colour Rendering Index nor Colour Discrimination Index were completely accurate predictors of the performance under different lamps.