<resources>

    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <item name="colorPrimary">@color/green</item>
        <item name="colorPrimaryDark">@color/green_dark</item>
        <item name="colorButtonNormal">?attr/colorPrimary</item>
        <item name="android:windowBackground">@color/gray_background</item>
    </style>

    <style name="ButtonTextAppearance" parent="TextAppearance.AppCompat.Button">
        <item name="android:textColor">@android:color/white</item>
    </style>

</resources>

<resources>

    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <item name="colorPrimary">@color/green</item>
        <item name="colorPrimaryDark">@color/green_dark</item>
        <item name="colorButtonNormal">?attr/colorPrimary</item>
        <item name="colorAccent">@color/green</item>
        <item name="android:windowBackground">@color/gray_background</item>
    </style>

    <style name="ButtonTextAppearance" parent="TextAppearance.AppCompat.Button">
        <item name="android:textColor">@android:color/white</item>
    </style>

</resources>

Use custom color accent used by progress bar
Use custom color accent used by progress bar
