Are you worried about the color of your teeth? Are they yellow? Stained? Don't panic, you are not alone. An unhealthy lifestyle, such as smoking and eating junk food, can easily cause yellow teeth. Here is one convenient home remedy you can try: mix baking soda with fresh lemon juice and gently brush your teeth with the mixed paste. Of course, it can't cause your teeth to sparkle instantly, but sticking with it will have a teeth-whitening effect.