Dark brown or orange-brown color. Orange and yellow warty shank porcini mushrooms usually turn dark brown or orange-brown when sautéed. During the frying process, the color of the porcini mushrooms will change from the original orange-yellow or orange-red to dark brown due to heat and oxygen. This is because some of the chemical components in the mushrooms undergo oxidation at high temperatures, resulting in the color change. After frying, the orange and yellow warty stalk porcini mushrooms not only change in color, but also change in taste and flavor, more fragrant and delicious.