I recommend the following:
The first product I recommend is Clear Mouth & Black Micellar Mouthwash. This is the most popular product. It is an antibacterial mouthwash for your teeth. If you are not a fan of antibiotics, you will appreciate the benefits of this product. If you have gingivitis, you should not use this product. It contains a small amount of salicylic acid and other bacteria-fighting ingredients. If you use this product, you will notice a difference within just a few days. You will see that you don't have any white streaks, or chipped or cracked teeth. You may even see your smile brighten!
The ingredient list is quite long, but I've listed it here for completeness and so you can make an informed decision. There are many companies out there making products that claim to "enhance" tooth tone, but the scientific evidence on those products is quite scarce. For example, some of the other products I've been told to buy contain vitamin C, which is a powerful anti-inflammatory. I am not going to use those products. I'm using the vitamin C-free version of the product I love to use – and it works much better.
You can also buy vitamin C products over the counter or in drugstores.