def opaque_legend(ax, fontsize=None, handler_map=None):
    """
    Calls legend, and sets all the legend colors opacity to 100%.
    Returns the legend handle.
    """
    leg = ax.legend(fontsize=fontsize, handler_map=handler_map)
    for lh in leg.legendHandles:
        fc_arr = lh.get_fc().copy()
        fc_arr[:, -1] = 1
        lh.set_fc(fc_arr)
    return leg