ax.fill_between 如何混合重叠的颜色？

Question

我有一个图表如下所示。

我使用 ax.fill_between 填充每条曲线下，但我想混合两条曲线重叠的两种颜色

    x1,y1 = df[Wav1], df[EQE1]
    ax.plot(x1,y1, color="darkcyan")
    ax.fill_between(x1, y1, facecolor='azure')
    
    x2,y2 = df[Wav1], df[EQE2]
    ax.plot(x2,y2, color="firebrick")
    ax.fill_between(x2, y2, facecolor='mistyrose')
   
    ax.scatter(x1,y1, color="darkcyan")
    ax.scatter(x2,y2, color="firebrick")