当你应用主题并希望改变颜色而不是

when you apply theme and want to change color than

EX：

activity.setTheme(R.style.green);


<style name="green">
        <item name="main_background">@drawable/background_green</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="button_light">@color/button_light</item>
</style>

主题颜色不能在特定主题的运行时更改。

如果要在应用程序中更改颜色，请设置自定义样式并更改这些样式。

Make custom style and change these styles when you want to change color in your application.