That seems like a good strategy, but it would result in needing a whole heap of colours.I think a better choice would be to make the generic stuff one color and then have the colors for the specific examples be variations on that color.
I use THICC 3.0 and one of the things I really like about it is that it has this system for certain regions. So if I don't like the generic Bavarian blue color or I think it doesn't contrast well with a neighboring country or even just the ocean depending on the map I use, I can pick from the twenty or so variant colors (including a few purplish colors and one greenish color, for variety).