In general Android OS leverages a “theme” to allow app developers to globally apply a universal set of UI element styling parameters to Android applications as a whole, or, alternatively, to a single Activity subclass.
So there are three mainstream Android OS “system themes,” which you can specify in your Android Manifest XML file when you are developing apps for Version 3.0 and later versions
I am referring the (APPCOMPAT)support library here:--
So the three themes are
1. AppCompat Light Theme (Theme.AppCompat.Light)
AppCompat Dark Theme(Theme.AppCompat),
And a hybrid between these two ,AppCompat Light Theme with the Darker ActionBar.( Theme.AppCompat.Light.DarkActionBar)
AndroidManifest.xml and see the tag, the android theme is mentioned as:-- android:theme="@style/AppTheme"
Open the Styles.xml and we have base application theme declared there:--
We need to override these parent theme elements to style the action bar.
ActionBar with different color background:--
To do this we need to create a new style MyActionBar(you can give any name) with a parent reference to @style/Widget.AppCompat.Light.ActionBar.Solid.Inverse that holds the style characteristics for the Android ActionBar UI element. So definition would be
We’ll reference this style definition inside the MyActionBar style definition, since the TitleTextStyle modification is a child element of an ActionBar parent OS UI element. So the final definition of MyActionBar style element will be