We've only lived in our brand new home for 1.5 years, and our carpet already has light patches! The carpet is that annoying tanish color that stains way easily, and it's stock manufactured home carpet, so it's not so great to begin with. A few weeks ago, I noticed a light patch in an area that would hardly ever be stepped on, even by our dogs. I don't think I've ever had to shampoo that area, except for in the summer when we had a guy shampoo the whole house. I decided to shampoo our carpets during Xmas break, and I'd barely begun when I noticed 2 more light patches! I highly doubt it's from our carpet cleaner. We use the same stuff the carpet guy used, and we've used it dozens of times without any problems. I decided to just let our carpet be dirty rather than risk any more damage, just in case. Ever had problems like this? I read a little about carpet dyes. Any experience?
If your home is a double wide (or larger), and you did not order it direct from the factory, then there is a good chance it sat on the dealer's lot for some time...and its possible some sunlight was allowed in thru the marriage wall. The marriage wall usually just has a layer of plastic over it for transport...some dealers leave it on while the home is on their lot, and some don't. Even a small hole in the plastic can result in a large faded area if it was facing the sun. (Some homes will sit on a dealerships lot for a year or so, before they are sold....plenty of time for the sun to cause some fading) There is also the possiblity that your cleaning chemicals did cause some fading....they all come with a warning to 'spot check' a section to see if they will cause any fading, before you are to use them all over the carpet. Since you mention dogs in the home, pet urine could also be a factor. And of course, there is always the chance that you just got a bad quality carpet to begin with. Different manufacturers use varying quality of carpet. Some are pretty good. Some are pretty cheap. A lot of the carpet being made today is synthetic...(some even use recycled plastic). Things like nail polish (or remover), or 'kool-aid' (its actually the sugar in the drink that does the damage) can actually alter the fibers chemically. Bleach dripped on the carpet will do the same, even if it is wiped up immediately. If a rag has been used to clean with bleach, or acetone (an ingredient found in most nail polish removers) is dropped on the carpet, or used when damp to wipe the carpet, it will cause the carpet to fade. If the carpet is in good shape, physically... little wear and tear, no holes, etc... then you may want to just have a professional come in to dye the carpet. Usually, this costs less than replacing the carpet, but get some quotes for replacing it too. Good Luck