Abstract: A color picture display device having a shadow mask is provided comprising a cathode ray tube (CRT) having a gun (1) for generating at least two electron beams mutually different colors and a display screen (2). The screen has phosphor deposits for emitting light of different colors. The device has a deflection system (3) for scanning the electron beams across the display screen (2) in a pattern of successive, substantially parallel lines, each line being scanned in a scanning direction. The device further comprises means for diverging the landing points on the screen for at least one of the beams with respect to one of the other beams in a direction other than the scanning direction, and means for interpolation of color video data, used to control the beam intensity, in order to reduce shift errors due to the diverged beams. Further, a method for operation of such a color picture display device is disclosed.