Make the target lock indicator (square box around the ship icon) in the Overview better distinguishable when someone in fleet applies a “friendly” module to you.
Ideally, the UI would let you pick your preferred color for this.
Add an option to the Misc tab on the overview settings window where the colour can be specified.
As I said in my thread in #issues-workarounds-localization I understand why the decision was made to change the default colour from yellow to purple. Each colour has a very special meaning in Eve, yellow means danger, purple means fleet, etc. The decision to make it purple was presumably to reduce the number of heart attacks in fleets, but it’s really really hard to see, and while the colour can be changed as detailed in my topic, it also changes the colour of other UI elements which alters their meaning and that is a problem.