CO2 laser around mouth: It's been 12 weeks and my skin is red and brown.

all CO2 lasers are not the same. even with the same laser you will have different results when performed by different doctors. I have been working with my CO2 lasers ( I have 4 of them) for more than 8 yrs. I have not had a problem in any of my patients (not yet). my advise would be to seek attention from your doctors office who did the procedure and see what they can do to help you with the skin discoloration.  

It is difficult to say exactly what is going on without photos.  It sounds like you have some hyperpigmentation as a result of the laser therapy.  You should contact your physician to discuss this.  Pigmentation will resolve on it's own over time. There are products and treatments however which will speed up the process.Your physician should be able to advise you.

It is tough to say without any photos, but pigment changes can occur following this type of aggressive laser treatment but usually can be addressed. I would continue follow up with your surgeon or get a second opinion with an in person consultation since that is the best way to formulate a plan. Either other lasers or some bleaching creams can sometimes be usedBest of luck