My plasma TV shows a blue vertical line in the picture if the screen shows a green or red image but when the image is blue the line is black if white the line doesnt show What is wrong with my TV?

The blue vertical line on your plasma TV indicates a potential issue with the display panel or the circuitry responsible for processing colors. It could be a failing pixel or a problem with the connections or drivers for the red and green subpixels. Since the line disappears against a blue image and doesn't show with white, it suggests that the blue subpixel is functioning correctly, while the others may be malfunctioning. You may need a professional repair or replacement of the panel to fix this issue.