I will elaborate in more detail:
My map has 9 levels of political relationship. All players start neutral to each other and each turn it is possible to either upgrade or downgrade a particular relationship. From neutral you can downgrade to uncooperative, then to unfriendly, then to hostile, and finally to war. Or you can upgrade from neutral to cooperative, friendly, aligned, and finally to allied.

Yes, I previously requested a feature whereby when you view political relationships these various stages could be color coded so that it is easier to see exactly where they stand. Right now they show in red when they are hostile or war, and in green when aligned or allied, but gray for everything else. This is because the color is hard set by the arch_relationship in the engine. I have looked at the code and think it would be fairly easy to change it but I'm not a java programmer so I don't know. In any event, that was an earlier thing but the subject of this thread is different:

I also have 18 players (countries). My game is a free-for-all, so often I am playing with a lot of AI players. Each turn the human players have to endure a lot of popup messages saying things like "Brazil is annoyed with Russia and has downgraded its relationship to uncooperative", or "Austria and India have improved their relationship to friendly". Unless the message concerns the nation I am playing I usually don't care about it. I realize it would be complicated to tailor it to individual players, so all I'm wanting (hoping is already possible) is at the player level to globally turn on or off all political messages. That way human players can decide if they want to see them or not as the game progresses.