In 1956, we came to the decision at the Budapest Technical University to start large scale experiments on color harmony. The experiments and the processing of the experimental results have been completed in 2006, after 50 years of research work. The focal point of the experiments published in the current article has been the practical experience that the span of intervals between saturations and brightnesses of the compositions influence the harmony content of the composition, namely they determine in what extent we perceive the color composition as a harmonic one. Within the framework of experiments compositions have been shown to the participants, first those consisting of color pairs featuring the same hues and saturations but different brightnesses then those consisting of the same hues and brightnesses but different saturations. The method of experiments consisted of comparisons in pairs. There were 780 compositions prepared for the tests. The number of elementary observations during the tests comprised 544 000. It has been established that the variation of harmony content as a function of brightness- and saturation-intervals could be described by a harmony function. It has been established that the variation of harmony content depending on brightness-intervals is not, but that of depending on saturation intervals is being influenced by the hues of colors of the color pair in the composition. It has been established that in case of compositions with the maximum harmony content the interval of brightnesses of the colors making the color pair in each case gives d30V (d9Y), the interval of saturations gives d30T or is near to it. (c) 2008 Wiley Periodicals, Inc.