Eyedropper Tool picks a color directly from the canvas and makes it the current drawing color. It is essential when you want to reuse an exact color that is already in the artwork.
Icon

This is the eyedropper icon, placed toward the far right of the toolbar.
In practice, many people use it temporarily from another tool instead of selecting the icon directly—for example by holding Alt and clicking the canvas while using the pen or bucket.
Effect
It reads the clicked pixel’s color information and applies it to the current color. Because it picks the actual pixel value instead of a visually similar approximation, it is useful when you want to keep additions perfectly matched to existing colors.
Shortcut
The default shortcut is Shift + I.
Related Shortcuts
Alt+ click: temporarily use the eyedropper while another tool is active- Hold
Space: temporarily pan the canvas
How to Call It from Other Tools
The most common pattern is the temporary call by holding Alt. For example, while drawing with the pen or erasing, you can pick a color on the spot without changing tools.

