This is not an answer, since I don't think we can have them where they are of use to us in this version of the Mac OS.
However I DO SEE COLORED LABELS within the subdirectory list that is available to me in OS 10.9.4 within the "save as" window. My labels were migrated over from a OS 10.6.8 computer to the newer one that is now running OS 10.9.4. It is interesting that the data is there, but Apple won't let us use it.
I have the same desire to have access to the much more visually useful "labels" in place of the new "tags" and to have color back in the sidebar. I've recently purchased a used MacBkPro that came with OS 10.9.2 installed. I did a migration of my files from another computer that is still running OS 10.6.8 and was sorely disappointed to see the backward functionality of this "upgrade". What is interesting is that the colors for the sidebar ARE also still available, just we're not allowed to see them. I discovered this when I tried a 3rd party piece of software called SideEffects -- for a short time I could see my subdirectory colors and their functional grouping via color in the sidebar. Unfortunately, SideEffects didn't consistently work; especially after I upgraded to OS 10.9.4.
Perhaps you should inform Apple that you need the labels for a more efficient work flow at this URL: http://www.apple.com/feedback/macosx.html
I ask you to give them feedback in the hopes that someday they'll comply. I would like to be able to have the option to either have color or gay on gray in the sidebar and to use BOTH labels and tags, since they essentially do two different things.