A colour harmony rendering index based on predictions of colour harmony impression

This study describes the development of a new measure intended to improve the description of light source colour quality. Previously, the authors have developed several colour harmony formulae to describe observers' impressions of colour harmony for two- and three-colour combinations seen under well-defined viewing conditions. One of the applications of these formulae is to quantify the distortion of colour harmony that can occur on changing from one light source to another. Based on the colour harmony predictions of these formulae for a sample set of colours seen under reference and test light sources a new light source colour quality metric, the `colour harmony rendering index', is defined. Two experiments were carried out to investigate the correlation between visual observations and this new colour quality metric.