White is not defined as a color in physics, but it is considered a distinct color in visual art. In physics, a color is visible light with a specific wavelength. White is not considered a color, since white light is a combination of all wavelengths of visible light.
Black is also not considered a color in physics, as it is the absence of visible light. A prism is often used to visualize white not being a color. Shining white light into a prism refracts the light into different wavelengths, creating a visual rainbow that illustrates white being a combination of colors.