> We’re also adding a fill tolerance slider, giving you control over how precisely the Fill tool applies color. To get started, select the Fill tool and use the slider on the left side of the canvas to adjust the tolerance to your desired level. Experiment with different tolerance settings to achieve clean fills or creative effects.

This tool would have been so useful 25 years ago when I had to manually recolour every pixel in the contour of the cool photo I was editing for my new desktop background because the fill tool didn't recognise the background properly.