How to connect the wires when changing from standard to electronic ballasts?
You follow the directions on the new ballast. Exclusively, and in detail. Most (but not all) modern ballasts ignore bi-pin tubes with heaters, so you (following the diagram) connect to both pins (at one end of the tube) with one color wire. But if the diagram shows otherwise, you follow it. 

In any case, you follow, exactly, the diagram on the new ballast. What the old ballast did is irrelevant and often different.