How does Meitu Xiu Xiu or the light and shadow magician dilute the local color?

There is a silhouette in the light and shadow. In free cutting, a region is circled by a box or circle. After it is selected, right-click the area and the "Feather" option will appear, and then adjust the feather degree yourself. I just found out today. Let's share it. If it is bright, you can also adjust it in brightness options and contrast. This is not clear, but you can try.