Which observation is NOT typically seen when potassium reacts with water?

During the reaction of potassium with water, several notable observations occur. One key phenomenon is that potassium reacts vigorously, often producing hydrogen gas, which results in fizzing or bubbling (this aligns with the observation regarding fizzing). The heat generated from the reaction is substantial enough to cause the potassium to melt, demonstrating that the metal not only reacts but also changes its physical state due to this heat.

While potassium does produce a brightly colored flame when it is burned, in the context of its reaction with water, it typically produces a lilac flame rather than a bright red flame. The red flame is more characteristic of lithium, another alkali metal. This distinction is crucial because it highlights that the specific observation associated with potassium's behavior in water is different from the one reflected in the question. Therefore, the presence of a bright red flame is not something you would expect to see during the reaction of potassium with water, making this the correct answer.