Sesame oil: It can make walnuts quickly colored and deepened, and can also be used to brush the colors of two walnuts with different shades. Chili oil: it can be used in the part of walnuts to fill the problem of light color. Olive oil: It can be used for the maintenance of walnuts, because olive oil is artificially purified, with few impurities, which basically has no effect on the color of walnuts. Usually,