Please note that these skins will only work with the Full Mode of Football Manager 2021, Football Manager 2021 Touch Mode Base Skins will be released after that version has been released.
As with most recent Football Managers for you to make certain changes in Football Manager 2021 you need to create a new skin. Thankfully over the last few years some more stuff has been moved out of the skins folder so you only really need the Base skin if you are wanting to edit the skin graphics, fonts or colours. If you want to edit the match graphics or the most of the panel xml files you no longer really need the base skins.
So to make things easier for people I've put up some base skins that are identical to the default skins that come with the game, so you can add new files/graphics to these without messing up the original skins, and anything that isn't located in these new skin folders will be taken from the default locations within the game.
For Football Manager 2021 at the moment you have three skins to choose from the Default (Purple) Skin, and two Dark Skins one based on the FM21 colouring (Purple accents) and one based on the FM20 colouring (Cyan and Yellow accents). Light Base Skins will follow but with no default light skin this year they require a bit more work.
I'll also upload the Dark (and when they are ready Light) Versions to the Steam Workshop later for those that want a Dark/Light skin but don't need to edit them.
Full instructions on when and how to use the Base Skins can be found on the download page, please ensure you read the page in detail before downloading the Base Skins as it will save you problems in the future.
If you have any further questions on the Base Skins please ask any questions in the Skinning Hideout on the Official SIGames Forums.