I use the Highlight Name Changes options as a visual aid before making changes. It would be good to make a distinction between three categories of changes: substituting, replacing and removing characters.
E.g.
Original filename: house
Apply Case (4): Title
New filename: House
The lower case h has been substituted with a capital H, so that could get one colour.
Original filename: house
Apply Remove (5): First n: 1, Add (7): Prefix: m
New filename: mouse
The lower case h has been replaced with m, so that could get another colour.
Original filename: house
Apply Remove (5): First n: 2
New filename: use
The lower case ho has been removed, so that could get a third colour.