如何在NavigationView中更改分隔符颜色？

I'm trying to use NavigationView to implement NavigationDrawer. I have added the separator by setting group id in menu. However I can't see the separator. I guess it is because the separator color is same as the background. So I want to change the separator color. But I find no way to change it. Can anyone help me?I'm trying to use NavigationView to implement N