Clear aligners like Invisalign have become a popular choice for straightening teeth because they are discreet, comfortable, and removable. One of their biggest benefits is that they are nearly invisible, allowing you to smile confidently during treatment. But if your aligners start to look yellow, that transparency can quickly fade. If you’ve noticed discoloration, you’re not alone. Here’s why clear aligners turn yellow and what you can do to keep them looking fresh.