Colored halo appears around imaged due to color gun misalignment.
Cause:
The color guns located in the display unit, which shoot the colors red, green, and blue at the screen, have become misaligned. Moving the monitor or old age can cause this to occur.
Solution:
Do one of the following:
1) Have a qualified computer technician repair the display unit.
2) Replace the display unit with a new display unit.
