In the Invert Colors program, what colors are Karel instructed to switch between?

The Invert Colors program typically involves Karel switching between two contrasting colors that represent opposites. In this case, the choice of red and blue serves as common examples of contrasting colors, making them an effective pair for demonstrating color inversion. This contrast allows for a clear visual change, thereby showcasing the functionality of the program effectively.

While the other options may involve colors, they do not represent as strong a contrast as red and blue do. For example, yellow and green are adjacent on the color spectrum and would not provide a stark visual difference when switched. Similarly, blue and green are also closely related colors, resulting in less noticeable inversion. Black and white provide a strong contrast, but are often less associated specifically with color inversion programming compared to red and blue. Thus, the choice of red and blue uniquely highlights the principle of inverting colors within the context of the program.