This fix was created for my own personal use to make the game feel more authentic with its presentation. If you have any suggestions for future updates, please feel free to recommend them.
This file is save game compatible (You have to copy the lnc file to the database folder your save is using)
Tested with 21.3.0 and 21.4.0
How to fix competition colours in FM 20211. Close or Quit the game (f the game is running).
2. Extract the contents of the pack to a temporary location.
3. Find the latest database folder (in this example, 2140)
\Program Files (x86)\Steam\steamapps\common\Football Manager 2021\data\database\db\2140\
/Users/[username]/Library/Application Support/Steam/steamapps/common/Football Manager 2021/database/data/db/2140/
4. Open the folder named `lnc` and then click into the `all` sub-folder.
5. Move the `FM21 Authentic Competition Colour Fix.lnc` you extracted into the `all` folder within `database\db\2430\lnc\all\`