An assessment method for evaluating colour rendering properties of light sources

Abstract We present an assessment method to evaluate how the spectral power distribution of light influences the perception of colours and small colour differences. Included in the method are several ways to measure properties of reflected light with a spectroradiometer, visual assessments of perceived colours, and a visual performance test that aims at identifying an individual minimum colour contrast visibility threshold. In a first application of the assessment method, we used a colour contrast test chart printed on paper and studied it under the illumination of three LED light sources, halogen light and daylight. We concluded that the visual performance test was effective for reviling visibility thresholds for colour contrasts and that the method has potential for understanding the influence of spectral power distribution on perceived colour and visual performance. The methodology can be useful for optimizing illumination for individual needs.