Apple changed the Finder’s appearance to 50 shades of grey way ahead of the movie. You’ve probably gotten used to it, but the Finder’s nicer in color. Download the free XtraFinder, set its preferences to “Show colorful icons in the sidebar,” and you’re all set. XtraFinder can do a whole lot more too– experiment! Its icon is in the menubar and looks like this:
Just a bit nicer in color.