Photoshop Color Adjustment image operation 5: leisurely repair fracture

Why does color mode solve this problem?

Because color blending mode creates a result color with the brightness of the underlying base color and the hue and saturation of the upper blend color. This preserves the grayscale in the image and is useful for coloring monochrome images and coloring color images.

In other words, the lower level to improve the contrast after the appearance of the fracture, and then use the upper hue and saturation to make up, but still retain the brightness of the lower-adjusted parameter values.