3 weeks after CO2 laser for pigment and still very red?

Thank you for your question. Depending on the strength of the treatment the redness can last for a month or more. It is always important to follow post care instructions and use products as directed. If you feel your redness or post care treatment is not right then i would suggest consulting with a Board certified Plastic Surgeon for a second opinion. 

I recommend following up with your Doctor about after care and recommendations to improve redness. PDT therapy and lasers (ProYellow, Excel V, VBeam) can improve redness and inflammation. I also recommend skin care with vitamin c, b5 hydrator, silicone based scar gels with growth factors and enzymatic washes with papaya enzyme. Sun protection is essential. Typically I do a combination of lasers like clear and brilliant, fraxel, viva 4-6 weeks after co2 to improve this along with microneedling/prp to get the best outcomes with texture and tone.  Please see an expert. Best, Dr. Emer.

Absent an face-to-face evaluation, it is very difficult to provide solid guidance.
Sounds as though you may be getting some irritation and inflammation. If so, you might consider backing off a bit on one or more of the suspect products and let things calm down. Inflammation can cause pigmentation on its own. 
Keep in mind, you are only 3 weeks post your 3rd treatment. This alone can contribute to the extended period of redness. 
It appears your provider has you on good products. I encourage you to visit your provider for a first hand evaluation. Some adjustment to your regimen may be in order. Your provider can best address your needs.  
Should you not get resolution within a couple weeks after you visit to your provider, it wouldn't hurt to seek a second opinion.
I sincerely hope your concerns resolve quickly and you obtain your desired outcome.  
Warmly,
Arbella Sarkis, MD

Even a fractional CO2 laser treatment can cause redness for 3 to 5 weeks when it is aggressive.  If this is your third treatment in less than a couple of years you would most likely stay pink longer.  It is very important to continue with your bleaching routine under the care of your doctor that performed the CO2 or your dark pigment may recur.  Continue with the products and stay in close follow up with your doctor because the products can cause inflammation which may lead to post traumatic hyperpigmentation.  This is a difficult problem to treat. Also, stay out of the sun and wear a hat and sunblock at all times.  All the best to you.  Alexis Parker MD