Discolored edges on my 36"wega sony t.v.

there is about a 5" x16" strip at the bottom left corner edge and a smaller area in the opposite upper corner of the screen, that its color is always out of tone with the rest off the picture. So the area in the bottom left is always green and the upper right is always red..

Someone told me that the tv has tubes that need to be converged and you can do this in this the menu somewhere..

I do do have the service manual or any paperwork....

Robert