Using the eyedropper tool
The eyedropper tool lets you pick up the exact color or an average of the colors around the selected area for use in another element.
1. Select the element where you want to pick a color.
2. Select the Eyedropper tool from the left toolbar.
3. Hover the Eyedropper tool over the element and click to sample the color you want.
That color becomes your new fill color.
Learn more about working with fill and stoke colors.