Hi, I’m the creator of a modding tool which creates an ingame mod for you, where you can select the colours for all eight players with a color picker.
The tool was somewhat popular a few years back, but then broke due to a game update.
I recently fixed it and made a lot of improvements. Just need someone else to verify it actually works not only on my system before making a proper post about it here and on reddit.
So please if you have 5 mins of time and want to help out write me a message 
(Don’t want to post the link to the tool in here in case there’s still a problem)
Thanks!