CRTs(Cathode Ray Tubes)are major display devices in computers. In practical cases

in order to display colors on a CRT on standard

we must do color calibration work for it

which is the problem of color notation conversion between the RGB space of the CRT and the XYZ space of CIE system. Neural networks is one of methods in color notation conversion. In this paper

we proposes a BP Neural networks with four-hidden-layer to perform the color notation conversion from RGB space to XYZ space in a computer controlled CRT system. The experimental results show our method is better than the method which using only 2~3 hidden layers

and the color conversion precision of our experiment is about 1.5 CIELUV units.