Based on earlier experiences of the colour mismatch phenomenon we investigated the colour matching with two types of visual experiments. First we confirmed the phenomenon with a white colour matching experiment using narrow band and broadband light sources illuminating white reflection patches. Secondly we made a colour matching experiment with more saturated colour stimuli. During both experiments the observers had the task to set the colour stimuli coming from the test side to that coming from the reference side of the arrangement. Using spectroradiometric measurement data we calculated chromaticities using the CIE standard colour matching functions and using a slightly modified set of CMFs kindly received from Dr. Wold. The calulations showed that using the modified colour matching functions the calculated colour differences will be smaller. This result is true in both matching situations. After the second series we came to the conclusion that the value of calculated colour difference is the function of the blue amount in the radiation.