Skin discoloration is a possible side effect of Condylox gel, although from reading a Medline Plus article at http://www.nlm.nih.gov/medlineplus/prin ... 03519.html
it seems this is a less common occurance compared with other side effects (such as irritated skin, redness and swelling, and so forth). It's possible the skin discoloration will self-resolve but give your health care provider a call and tell them about any side effecs you've experienced, to see if they recommend anything specific for you.
If we come across more information I'll update this post.
Hope this helps.
All the best,