Final answer:
To change light's color, you need to alter its frequency or wavelength, as both are inversely proportional in the electromagnetic spectrum.
Step-by-step explanation:
To change the color of light, you must change either the frequency or the wavelength of the light. In physics, these two properties are inversely proportional to each other due to the constant speed of light. As the frequency of light increases, its wavelength decreases, and vice versa. Each color of visible light corresponds to a specific frequency and wavelength. For example, blue light has a higher frequency and a shorter wavelength compared to green light.
This fundamental principle underpins the phenomenon of color variation in the visible spectrum, with shorter wavelengths corresponding to higher frequencies and, consequently, colors perceived as more "blue" in the case of visible light.