pdb doesn't support colorization. However, it's not that hard to get it, even if you're a command-line addict (as I am;-) -- you don't have to switch to GUIs/IDEs just to get colorization while debugging Python. In particular, command-line tools usually work much better when you're accessing a remote machine via SSH, saving a lot of the bandwidth and latency issues that any remote access to GUIs and IDEs can inflict on you;-).
Specifically, for the task you're asking about, consider ipdb (you also need ipython, which offers a far more advanced shell than plain interactive Python, on which ipdb relies). Both offer you good tab completion, enhanced tracebacks, and colorization -- ipython for your normal interactive work, ipdb with the same features when you're debugging (otherwise just about the same as pdb).
In case someone hit the problem with colorization in a console.
My console had white background while ipdb was also adding rather light colors to syntax (for example variables were white). Pressing man ipython shows that we have 3 colors available: 'nocolor', 'linux', 'LightBG'. Ipdb was in my case installed via easy_install into my virtualenv. So it was trivial to look into ipdb source and modify it (hint search for ipdb/init.py in your env). Then I've modified following:
def set_trace():
ip = ipapi.get()
+ def_colors = ip.options.colors
+ def_colors = 'LightBG'
Pdb(def_colors).set_trace(sys._getframe().f_back)
It's a kinda hackish solution but well its for debugging purpose on my working station so its sufficient. But if anyone finds something better. Please send me a message on what to do.