Final answer:
To achieve white light, two additive primary colors of light must be combined. This process is known as additive color mixing and it involves the primary colors red, green, and blue. When mixed in the correct proportions, these colors result in white light.
Step-by-step explanation:
To get white light, you need to combine two additive primary colors of light. Additive color mixing involves combining the primary colors of red, green, and blue light, which are shown on the color wheel. When these colors are mixed in the correct proportions, they produce white light. This can be contrasted with subtractive color mixing, which involves combining the pigment primary colors such as magenta, yellow, and cyan to produce secondary colors.
For example, when red and green lights shine on a white paper, they mix to create the perception of yellow, one of the secondary colors of light. It's the additive mixing of colored light that's used in technologies like theater lighting and television screens. In this context, when all primary colors are added together, the resulting color is white, which demonstrates the principle of additive color mixing.