About the colors, @Beleg: The fewer colors you use, the harder it is to distinguish between countries. Using more subdued, medieval-ish colors would make the issue worse. If you only want to see colored borders with natural terrain colors, just click on the first filter (hotkey 1) and you are good....

UI- area suggestion: change how provinces are coloured. Overall UI of the game is extremely uneven. Great and truly immersive event pictures and decorations (kudos for artist!), tabs are okay-ish with its brown/gray palette, but these pink, bright yellow and seledine ownership-coloured map is nightm...