Which type of hair color is known for providing a long-lasting change and contains ammonia?

Permanent hair color is recognized for providing a long-lasting change to the hair color and contains ammonia as a key component. The inclusion of ammonia allows the pH level of the hair to be raised, which in turn opens the hair cuticle. This enables the dye molecules to penetrate deeply into the hair shaft and produce a more durable color change that can withstand multiple washes.

The advantage of ammonia in permanent hair color lies in its ability to achieve significant alterations in hair color, including lightening natural pigment and covering gray hair effectively. This process typically results in a vibrant and enduring color that can last for several weeks or months, unlike other types of hair colors that either wash out more easily or require more frequent application to maintain the desired hue.