Final answer:
The product responsible for making another color more vibrant and intense is a pre-lightener. This is typically used in hair coloring processes before the application of the new dye to ensure the color appears more vibrant.
Step-by-step explanation:
What makes another product more vibrant, intense, purer, or stronger? The correct answer is a pre-lightener. A pre-lightener, such as bleach, is used to remove the natural color from hair before applying a new color, which allows the new hair color to appear more vibrant and intense. Permanent hair coloring requires components including an amine (like 1,4-diaminobenzene or 2,5-diaminotoluene), a coupling agent, and an oxidant, and it typically operates under basic conditions. The pre-lightening process involves oxidation, which lightens the hair, and it prepares the hair for the subsequent application of a new, more vibrant color.