What type of hair color is considered semi-permanent?

Semi-permanent hair color is specifically designed to last for a limited number of shampoos, typically around 4 to 12 washes, depending on hair type and the product used. This type of color doesn't contain ammonia, which makes it less damaging to the hair compared to permanent hair color. Semi-permanent color works by coating the hair shaft rather than penetrating it, allowing for a more gradual fade as the hair is washed. This feature makes it an excellent choice for individuals looking to refresh their color or experiment without a long-term commitment.

The other options describe qualities associated with different types of hair color. For example, formulations that contain ammonia are generally permanent and alter the hair structure more significantly, which is inconsistent with the definition of semi-permanent color. Descriptions that suggest a permanent change or focus solely on temporary highlights refer to entirely different coloring processes not encompassed within the semi-permanent category.