Labels X adds file labeling features into Mac OS X. This means, you can apply various color tints to file icons, and sort the files by label. This gives you more freedom and options in organizing your files. Additionally, Labels X shares file label information with Mac OS 9, so you’ll see the labels in both Mac OS 9 and Mac OS X.
Apply color tint labels to Finder icons
Add “Label” column to Finder list view to sort files by label
Easy-to-use contextual menu to view and change labels for files
Simple preference pane with an ability to change label names and colors
Labels X is shareware with no features removed for first 15 days. More info and download link here