Eye dropper is one of the drawing tools. This tool enables you to catch the color of pixel of your character. This will set the current color to the color you clicked on.
This tool is located at:
|Tool bar||Menu bar||Shortcuts|
|Drawing > Eyedropper||Shift + P|
Then simply click on your character for the color you want. This color will then be set to the current one.
You may also use the eyedropper when drawing with the pen or the bucket. To do this, hold Shift and click on your character like you would with the eyedropper.