The classification of color pastes includes base colors, tints, and normal color pastes, each serving a distinct purpose in hair coloring. Base colors provide natural, chromatic shades for gray coverage and color foundations, tints offer hue adjustments for customizing or correcting colors, and normal color pastes are pre-formulated blends of base colors and tints for quick, consistent results when mixed with hydrogen peroxide. The numbering systems used for these products help identify their depth, hue, and intended use in hair coloring applications.

. Base Colors:

Base colors are hair color pastes designed to impart a natural-looking, chromatic shade without any additional hue adjustment. They are primarily used to cover gray hair effectively and provide a solid foundation for further color customization. The numbering system for base colors typically follows this format: XX/0, where XX represents the level (depth) of the color on the hair color chart.

• 2/0, 3/0, 4/0, 5/0, 6/0, 7/0, 8/0: These numbers indicate the darkness or lightness of the base color, with lower numbers representing darker shades (e.g., 2/0 for very dark brown) and higher numbers indicating lighter shades (e.g., 8/0 for light blonde). The "/0" suffix signifies that no additional hue has been added to the base color.

2. Tints (Coloring):

Tints, also known as color modifiers or toners, are hair color pastes that contain only hue (without chroma) and are used to adjust the depth, tone, or shade of a given color. They can be used to counteract unwanted tones, enhance specific shades, or add subtle color variations to a base color. Tints are identified using the following numbering system: 0/XX, where XX represents the hue code.

• 0/22, 0/33, 0/43, 0/45, 0/66, 0/88, 0/11: These codes denote specific hue directions or undertones. For example, 0/22 might represent a violet-based tint, 0/43 could be a copper-based tint, and 0/66 might indicate a cool ash-based tint. The "0/" prefix indicates that these products do not contain chroma and are intended for modifying or adjusting existing colors rather than providing a standalone color result.

3. Normal Color Pastes:

Normal color pastes are ready-to-use hair color formulations that combine a base color and a tint (if necessary) to create a specific, predetermined shade. They are designed to be mixed with hydrogen peroxide and provide a fast, stable color result after application. The numbering system for normal color pastes combines the base color and tint codes:

• 6/11, 6/45, 6/43, 6/66, etc.: These codes represent a specific color shade that combines a base color (the first number) and a tint (the second number). For instance, 6/11 might be a light brown shade with a violet undertone, while 6/45 could be a light brown shade with a copper-red undertone, and 6/66 might be a light brown with a cool ash undertone.