Hi again,
Since this is all seems very much up in the air still, I thought I would post again, my explanation may have been convoluted but I'm not sure if my proposal was really understood.
I'm not suggesting for there to be less colours possible - in fact the opposite, we could easily have 30-40 different shades where players can then pick one they like, I know this becomes part of player recognition in the games.
What I recommend is that we have 16 set colour 'categories' if you will, and then within those we can have some different tones and shades players can choose from - but still obviously a red or a dark blue so other players can refer to them easily.
Below I have the current red, green, blue and yellow we have now (or at least it should be, they are taken from a screenshot of the lobby). And then some different versions players could choose from.
The important thing is that, in any game there is only one 'red' or 'green' player so any similarity between the tones won't be relevant.
I would expect players could choose their desired preference order in their profile, for a custom game it would be first in best dressed, TMM could go on rank, highest player gets their first choice, and then so on.
As to accessibility for colour vision impaired players, I had a look at your links Uveso, and it seems we can get a rough equivalent by choosing specific tones which can be distinguished. I found a 16 colour palette at https://github.com/filipworksdev/colorblind-palette-16, which I have included below with a rough mapping to the colours I mentioned earlier.
Note the last column in the first image is of these colours which is why they may seem a bit off So this could be set as the default selection for these players, and they would soon be able to learn which colour players are referring to in-game.
You could definitely have some settings for defaults if you are casting for example so they stay the same - if playing you could choose if you want to show other players choices or only your own, it could be quite flexible.
One last thing I am wondering on, is if the strategic icons could show white unit symbols instead of black for the darker colours as this would be a big aid to visibility! Unsure if possible to load a reversed icon set based on team colour.