The experiment conducted with the NOKIA Multigraph 447Xpro presented in this article shows that a change of colour temperature results in a change of general colour appearance displayed on the CRT screen. However, it does not considerable affect chromatic coordinates of RGB monitor primary stimuli. The change of :a produced colour appearance which it causes can have a considerable influence on colour matching - at tłie stage of map designing on the screen. Discordances among given colour temperature set-up in lhe screen menu in relation to computed by means measurements of colour temperature are shown. Of computing and Methods of colour temperature calculating and setting are given. It has been stated which channel has a critical (decisive) influence on a colour temperature setup.