Yellow teeth can occur for many reasons. As you mention, tobacco (smoked or even smokeless, such as chew) can stain your teeth permanently yellow or brown. Other common things that can do this include coffee, sugared drinks, and poor oral hygiene. Some people who are mouth breathers will also experience some increased staining and yellowing of their teeth. Fortunately, there are excellent solutions for this problem due to advances in dentistry. The first step is to speak with your dentist
to make sure that the health of your teeth is appropriate. If they have been well cared for and have no serious issues, then you can discuss cosmetic approaches, including teeth whitening and other options, which many people tolerate very well with excellent results. There are many options available, some of which work better than others, and your dentist will be able to recommend which is right for you. Additionally, he or she will likely be able to suggest what is the likely cause of the staining so that you can make corrections to avoid further staining in the future. Please speak to your dentist about your oral hygiene and what can be done to approve both the health and cosmesis of your mouth.