The clinical manifestations of café-au-lait spots are light brown to dark brown spots or patches, which look like a mixture of coffee and milk, so they are also called café-au-lait spots; Mongolian spots are special gray-green or blue café-au-lait spots of varying sizes. , round, oval or irregular in shape, with clear boundaries and smooth surface; Mongolian spots are round or map-shaped spots or patches, 0.5-12cm in size, or even larger, with consistent color and blurred edges.