How can I label things in the Dock?
Try this, it's a bit of a kludge but it should work:


Open /Applications/Xcode.app/Contents/Resources/xcode-project_Icon.icns in an editor like Preview or GIMP.
Select whichever resolution you want to modify.
Add whatever text you want, e.g. the project workspace name.


Side note: This may ask you to duplicate the file before editing it. Don't worry about this.

* Do not save this! * (You probably won't be able to anyway.)
Press File > Save As... while holding Option, or press ⇧⌥⌘S, and save it as a PNG somewhere, if you want to keep it around. (I would recommend this, but you certainly don't have to.)


If you're using a third-party image editor like GIMP, you may not have to use the Option key.






Open the PNG you just saved. (Or if you chose not to save it, ignore this step.)
Select All (⌘A), and copy it (⌘C).
Go to the project you want to change the icon of.
Press File > Get Info (⌘I).
Click on the icon in the top left of the info window, and paste (⌘V).




The second part of this also works for any icon you might have laying around! You can change  the icons of anything, including folders and even apps, this way. (But if you're changing an app icon, be aware that some apps change their own icon while they're running. It'll change back when the app quits. For example, Firefox does this when downloading a file.)