White drawing refers to line drawing without color. Use a brush to outline the skeleton and then render the colors. The first stage is called line drawing and line drawing. There are also line drawings without color, also called line drawings, like the Eighty-Seven Immortals Scroll, which use lines alone to show the artistic style.
Rendering refers to applying colors, such as leaves. First use cyan to create a base color, then blend it with a water pen and color pen, and then dye the cover with green, so that the layering appears.