Hair coloring is the process of changing the color of hair using various products. This can be done for aesthetic reasons, to cover gray hair, or to express personal style. There are different types of hair color, including permanent, semi-permanent, and temporary dyes, each offering varying levels of longevity and vibrancy. The application of hair color can be done at home or in a salon by a professional hair stylist. Techniques such as highlights, lowlights, and balayage can create depth and dimension. Safety precautions, like performing a patch test, are important to avoid allergic reactions.