Final answer:
Two colors of light that add together to form black are known as complementary colors, as they cancel each other out, resulting in the absence of light perceived as black. Option 2 is correct.
Step-by-step explanation:
The two colors of light that add together to form black light are called complementary colors. In additive color mixing, which applies to light, not pigments, primary colors (red, green, and blue) mix to form secondary colors (cyan, magenta, and yellow), and all colors added together in equal proportions create white light.
However, when specific colors are missing from white light, our eyes perceive the complementary color. For instance, removing red photons from white light makes us see the color green. Therefore, while mixing pigments to achieve black involves combining multiple colors, with light, achieving black would imply the absence of light altogether.
When all colors are added together, the result is white light. On the other hand, when all colors are subtracted, the result is no color, or black. The colors that add together to form black light are called complementary colors. These are the colors that are located opposite each other on the color wheel, such as red and green or blue and orange.