What panel helps to save color definitions for reuse in Illustrator?

The Swatches panel is the key tool for saving and managing color definitions in Adobe Illustrator. This panel allows users to create and organize a collection of colors that can be easily accessed and reused across different projects. By saving colors as swatches, you can maintain consistency in your design work, ensuring that the same colors are applied throughout various elements or parts of your illustrations.

When you create a color in Illustrator, it doesn't automatically become a swatch. To reuse it, you can add it to the Swatches panel, making it readily available for future use. This feature is essential for designers who want to streamline their workflow and achieve a cohesive color palette across their designs.

The other panels serve different purposes: the Color panel primarily allows you to mix colors and adjust their components, the Brushes panel is focused on brush presets for stroke and texture effects, and the Symbols panel stores reusable vector graphics known as symbols. Thus, while each panel has its specific function, the Swatches panel is distinctly designed to manage and preserve color definitions effectively.