Effects of lightness and chroma on colour harmony of colour pairs

In addition to quality and usability of products, colour is an important factor which affects a customer’s decision when buying a product. Designers should therefore consider a combination of colours in order to design most outstanding and pleasing products. This study aimed to investigate impacts of lightness and chroma of colour pairs on the degree of perceived colour harmony. Colour samples were divided into 2 sets: 42 single colours were chosen for the lightness investigation, and 33 single colours for the chroma. All possible combinations of single colours were generated to obtain 861 and 528 colour pairs, respectively. The colour pairs were shown one by one on a CRT monitor as two colour squares placed next to each other against a uniform grey background. Twenty Thai observers, all having normal colour vision, participated in the experiments in which they were asked to rate the degree of colour harmony for each colour pair using a 10-point scale (-5 means completely disharmonious to 5 means completely harmonious). Experimental results indicated that lightness and chroma had impacts on colour-harmony scores of colour pairs. Colour pairs with high lightness were more harmonious than those with low lightness and similar results were also found in the case of chroma. The most harmonious colour was white and the grey was the most disharmonious