What color will result in a shortened process time when using a lightener on gray hair?

The correct answer is orange. When lightening gray hair, achieving the right undertone is essential for effective color results. Gray hair typically has a neutral base, and during the lightening process, it can be more challenging to achieve a bright or vibrant color due to its lack of pigmentation.

Using orange as a lightening color is effective because it complements the underlying pigments found in gray hair. In the hair color wheel, orange is opposite to blue, which means that when orange is present, it can effectively neutralize the blue undertones that can emerge during the lightening process. This results in a faster color change and aids in achieving a more natural blonde shade more quickly.

Choosing colors like blue, yellow, or purple would not yield the same efficiency in this context. Blue may result in unwanted cool tones, yellow could potentially result in a fading or dull blonde, and purple is often used to neutralize yellow tones but may not be the most efficient when aiming for a quick and effective lift on gray hair. Therefore, orange stands out as the most suitable choice for reducing processing time.