What is the difference between semi-permanent and demi-permanent hair color?

Demi-permanent hair color is distinguished by its composition and longevity, which makes option C the correct choice. This type of dye typically lasts longer than semi-permanent hair color, usually around 20 to 28 shampoos. The inclusion of a small amount of ammonia in demi-permanent color allows it to penetrate the hair shaft more effectively than semi-permanent color, which does not lift the natural hair color. This property enables demi-permanent color to provide richer, longer-lasting results while still being less damaging than permanent color.

The other options present variations that do not align with the characteristics of these types of hair color. For example, demi-permanent color does not contain a large amount of ammonia, as that would be more characteristic of permanent color. Semi-permanent color generally does not need a developer, which distinguishes it from demi-permanent. Lastly, it’s important to clarify that semi-permanent color is not permanent; it is designed to gradually wash out without chemically altering the hair structure like a permanent color would. Understanding these differences is essential for selecting the appropriate hair color treatment based on desired outcomes and hair condition.