Fuzzy Select works by selecting an area of the image that contains variations of a color. Click an area, and the Fuzzy Select tool selects a different portion of the image.

Here it is called the “Fuzzy Select” tool. It sits just to the left of the “Select by Color” tool that while largely similar offers one extra function.

Now double-click on the fuzzy select (magic wand) tool in The GIMP toolbox window to see the tool options. You'll need to experiment with the Threshold setting, but generally you'll want to increase ...