I recall my grandfather panicking when I attempted to adjust the tint on his TV. He said that he would have to call the TV people to come and re-align it. I thought he was crazy at the time, but later learned this was a very real problem in early color televisions, and that getting the three guns to align on the screen properly was apparently something of a task.

So...

1. is this true? I assume with a one-gun system like Trinitron this wasn't an issue in the first place, but even with a delta it's not entirely clear to me what the issue is - one gun not passing through the focus of the deflection system?
2. how did they fix it? I certainly don't recall any TV from, say, 1980 on having these sorts of issues or any controls for addressing them. This suggests there was either some way of eliminating the effect entirely, or perhaps an auto-adjustment system