I'm using my own icon theme, which inherits from gnome. Look at pling for a theme that suites you. Note that there are also "icon subsets".
Elementary or Mint themes are rather close to the gnome theme (in fact they inherit from them) - so the next update of the gnome icons won't bother you very much.
The advantage of having your "own" icon theme is, that you can extend it any time or change only certain icons.
Someone implemented blue folder icons. You might change the entry Inherits=to "gnome,hicolor" in the file index.theme
To make this clear: You will have to download these icons and copy them into /usr/share/icons. With gnome tweaks, you will select your new icon theme. Since this theme was introduced from the outside, it will not be updated, since they are not known to your package manager.
Why does Ubuntu have not "blue folders"? The changes have been made upstream, and it'll take a while until they reach this distro. Since you have the gnome theme installed, you can switch any time after an update brought the new blue icons. Meanwhile, you use your downloaded theme without any interference.