Let me emphasize again: A change between 4 on a4 or h5 and 5 is not possible.
Some examples.
Bischoff on d1 to the left:
Standing on a4 after the move, a color transfer is not possible. Standing on 4 after the move, then a color transfer is possible. Because from there you can continue in the next move via b5, c6 etc., a color change has taken place.
Bishop on d1 to the right:
The move can go up to 5 (and not h5, this square cannot be occupied). The next move can be continued via g6, f7 etc. There has also been a color change.
For the other half of the board everything is vice versa.
Let me emphasize again: A change between 4 on a4 or h5 and 5 is not possible.
Some examples.
Bischoff on d1 to the left:
Standing on a4 after the move, a color transfer is not possible. Standing on 4 after the move, then a color transfer is possible. Because from there you can continue in the next move via b5, c6 etc., a color change has taken place.
Bishop on d1 to the right:
The move can go up to 5 (and not h5, this square cannot be occupied). The next move can be continued via g6, f7 etc. There has also been a color change.
For the other half of the board everything is vice versa.
Does that answer your question?