Coloured files and folders - Mavericks and Yosemite
In the App Store a tool called "Foldery" is available. It doesn't change the color of the label, but the color of the folder icon itself. That does the job for me to separate more important things from the lesser important ones - at least on the Desktop.

This only works for folders and not for documents, of course. But it might fill the void left by Apple's strange decisions partially.

I also would love the get the old label colours back, the little dots are hardly useful and especially hard to see from a distance.