Suleyman
Thank you.
There are new colors in EU II, but "flawed" in my opinion, so I have made my own mod's. The colors are nice, but like the original Russia color, and the dark grey, much too dark for several of the colors. I have modified them to be just a little lighter. I was very fond of the color I accidently assigned to Russia in EU I, but in EU II, I went with a lighter version of the dark brown "Russian bear". My EU I color is used for other countries. I do regret Russia losing that color, it seemed regal to me.
Oddly, that "ugly, medium green" looks good now. Seriously, not because the new colors are ugly, but with more country colors it now does not look "odd" anymore. To your question, in EU I, that color cannot be changed.
Like the ugly, medium green, the brown used for Denmark looks better (though, still, my least favorite color). Just having 2 or 3 new colors has made the overall palette much nicer.
Another nice feature of EU II (I hope I'm not punished for violating the NDA with all this) is that you can select (by hacking the files) what color each country gets.