There is this useful information and everything works well: http://docs.appcelerator.com/platform/latest/#!/guide/Android_Themes
The image is also very helpful:
The problem is that I want to have white or very light gray in the top bar. When I set this as "android:textColorPrimary", however, the text is white in the top bar, but in all alerts for instance as well making it invisible/very difficult to read.
How can I set the text color of the bar to white and theme the alert messages and other text in the default text color (dark gray)?
The themeAndroid.xml in app/platform/android/res/values looks like this
<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:android="http://schemas.android.com/apk/res/android">
<style name="materialTheme" parent="@style/Theme.AppCompat.Light">
<item name="colorPrimary">#2e7d32</item>
<item name="colorPrimaryDark">#005005</item>
<item name="colorAccent">#80d8ff</item>
<item name="colorSwitchThumbNormal">#49a7cc</item>
<item name="android:colorButtonNormal">#49a7cc</item>
<item name="android:textColorPrimary">#DADADA</item>
<item name="android:spinnerItemStyle">@style/SpinnerItem</item>
<item name="android:spinnerDropDownItemStyle">@style/SpinnerDropDownItem</item>
</style>
If you want to style the color of the actionbar font you need to extend your theme like this:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="Theme.MyThemeActionbar" parent="Theme.AppCompat">
<item name="colorPrimary">#FF0000</item>
<item name="colorPrimaryDark">#000000</item>
<item name="actionBarStyle">@style/CustomTheme.ActionBarStyle</item>
<item name="actionBarTheme">@style/Theme.ActionBarTheme</item>
<!-- tab -->
<item name="actionBarTabTextStyle">@style/TabStyle</item>
<item name="android:actionBarTabTextStyle">@style/TabStyle</item>
</style>
<style name="Theme.ActionBarTheme" parent="style/Widget.AppCompat.Light.ActionBar">
<!-- actionbar arrow -->
<item name="colorControlNormal">#ffffff</item>
</style>
<style name="CustomTheme.ActionBarStyle" parent="style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
<!-- actionbar -->
<item name="elevation">0dp</item>
<item name="android:actionMenuTextColor">#FFFFFF</item>
<item name="android:titleTextStyle">@style/CustomTheme.ActionBar.TitleTextStyle</item>
<item name="titleTextStyle">@style/CustomTheme.ActionBar.TitleTextStyle</item>
</style>
<style name="CustomTheme.ActionBar.TitleTextStyle" parent="@android:style/TextAppearance.Holo.Widget.ActionBar.Title">
<!-- actionbar font -->
<item name="android:textColor">#FFFFFF</item>
</style>
<style name="TabStyle" parent="style/Widget.AppCompat.Light.ActionBar.TabText">
<!-- tab font -->
<item name="android:textColor">#ffffff</item>
</style>
</resources>
Then you can set the font color and the primary color to a different value and leave other thinks to the default values