Soothely
Rooibos is fine. Red wine is not. Here is why the difference matters.
For roughly forty-eight hours after you start whitening, your enamel takes on pigment more readily than usual. Anything that would stain a white cotton shirt will stain your teeth faster than it normally would, and the effect is temporary but real.
Whitening temporarily increases the permeability of the enamel surface. The surface is fractionally more open and fractionally more receptive, and the pellicle, the thin protein film that normally coats your teeth and acts as a barrier, has been disrupted. It takes about two days for that film to rebuild.
This is true of any whitening chemistry, gentle or not. It is not a peroxide-specific problem.
Avoid for two days: red wine, coffee, black tea, cola and dark fizzy drinks, beetroot, soy sauce, balsamic vinegar, curry and turmeric, tomato-based sauces, berries, and anything with strong artificial colouring.
Fine throughout: rooibos, white wine, clear spirits, milk, water, plain yoghurt, chicken, fish, rice, potatoes, cauliflower, white cheese, and peeled apples or pears.
The quick test: if it would stain a white shirt and you would be annoyed, it will stain your teeth in this window. Rooibos passes that test despite looking dark, because the pigment structure is different.
Tar deposits onto the tooth surface directly and the window makes it worse. There is no way to phrase this that makes it optional. If you smoke, the first two days after starting will undo a meaningful part of the progress, and continuing will pull the shade back over the following weeks.
Use a straw for anything dark and cold, which keeps most of the liquid off the front surfaces. Rinse with plain water immediately after anything on the avoid list rather than brushing, because brushing a freshly acid-exposed surface is worse than leaving it. Wait thirty minutes before brushing after coffee or wine.
If you cannot give up coffee for two days, and most people cannot, drink it quickly rather than sipping over an hour. Contact time matters more than volume.
Normal diet resumes. The shade you hold long term depends far more on what you drink every day for the next three months than on what you did in the first forty-eight hours. A daily coffee habit will pull the shade back gradually whatever product you used.