What essential tool is used for applying hair color?

The essential tool used for applying hair color is the tint brush. This tool is specifically designed for the application of color to hair, allowing for precision and control. The tint brush's bristles help to distribute the color evenly and reach all areas of the hair, whether applied to roots or lengths. Its design often includes a long handle, which aids in maneuvering through sections of hair during the coloring process. This ensures that the color is applied effectively, resulting in a more uniform and vibrant outcome.

In contrast, scissors are primarily used for cutting hair, a comb is utilized for detangling and sectioning the hair, and a curling iron is meant for styling purposes by creating curls or waves. Each of these tools serves a distinct purpose that does not align with the application of hair color, making the tint brush the most appropriate choice for this task.