Develop Reference

Editing activity theme

I'm trying to edit theme like this:
<style name="MyAppTheme" parent="#android:style/Theme.DeviceDefault.Light.DarkActionBar">
<item name="android:background">#color/colorPrimary</item>
</style>
But this colours my whole activity. Instead I want only action bar to be coloured with my custom color. How to achieve this?
Edit:
I've managed to achieve desired result by using Theme Editor and creating custom theme with it.

Try this
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
and please read this for more info

Use AppCompat theme. Specify colorPrimaryatribute since the ActionBar background color depends on it.
<style name="MyAppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="colorPrimary">#color/colorPrimary</item>
</style>

Also you can try it like this ,
Use a parent style and declare your whatever Widget style inside the parent one.Here use android:actionBarStyle
See the example below
<resources>
<style name="MyTheme" parent="#android:style/Theme.Holo.Light">
<item name="android:actionBarStyle">#style/MyActionBar</item>
</style>
<style name="MyActionBar" parent="#android:style/Widget.Holo.Light.ActionBar">
<item name="android:background">ANY_HEX_COLOR_CODE</item>
</style>
</resources>
set MyTheme in your activity
Note : ActionBar will not work for your target environment which is at API level 10

Android actionbar background around title

Android Studio 1.1.0. SDK 22 Installed&Compiled, SDK 17 Target (I suppose it's not relevant, because issue occurs also on preview in IDE).
I started playing with Holo theme action bar styling and ran into an issue, involving background color. This is my styles.xml:
<resources>
<style name="AppTheme" parent="android:Theme.Holo.Light.DarkActionBar">
<item name="android:background">#ff0d3200</item>
<item name="android:actionBarStyle">#style/BarTheme</item>
</style>
<style name="BarTheme" parent="android:Widget.Holo.ActionBar">
<item name="android:background">#443322</item>
</style>
</resources>
And this is output. I want app title's background color to be the same as action bar's. As I've said, it's the same on the preview, so I don't think it's because my phone(SDK17) or emulator. Overflow button behaves the same way, there just isn't any in this case.
I tried setting android:titleTextStyle in BarTheme to this style:
<style name="TitleTheme" parent="android:TextAppearance.Holo">
<item name="android:background">#443322</item>
</style>
But it didn't change a thing. What do I do to overcome this?

try ,
<style name="AppTheme" parent="android:Theme.Holo.Light.DarkActionBar">
<!-- All customizations that are NOT specific to a particular API-level can go here. -->
<item name="android:actionBarStyle">#style/MyActionBar</item>
</style>
<style name="MyActionBar" parent="#android:style/Widget.Holo.Light.ActionBar">
<item name="android:background">value</item>
<item name="android:titleTextStyle">#style/TitleColor</item>
</style>
<style name="TitleColor" parent="android:TextAppearance.Holo.Widget.ActionBar.Title">
<item name="android:textColor">value</item>
</style>

Due to David's input I solved my problem myself. I had to set windowBackground, instead of background in AppTheme. I'm not sure what is the exact difference, but it works properly. Remember not to change attribute in your BarTheme, because it won't work with windowBackground. Therefore correct styles.xml file is:
<resources>
<color name="bcColor">#ff0d3200</color>
<style name="AppTheme" parent="android:Theme.Holo.Light.DarkActionBar">
<item name="android:windowBackground">#color/bcColor</item>
<item name="android:actionBarStyle">#style/BarTheme</item>
</style>
<style name="BarTheme" parent="android:Widget.Holo.ActionBar">
<item name="android:background">#443322</item>
</style>
</resources>
Note that color has to be defined as resource in this case and cannot be hardcoded. The clean way to do this is create colors.xml in values folder and define all colors there.

Styling my app with custom colors

I'm trying to apply some styles to my app. I've created a custom theme for the ActionBar using this actionbarstylegenerator.
But I want to change also in my app, the stock blue Holo color, to a red one, at least on buttons.
So, I have the custom theme for the ActionBar (Compat), and for the other side, a custom theme to change the Holo color.
In my app, I have defined the custom theme for the Actionbar, and I want to set the custom Holo theme inside the Actionbar's theme, but I don't know how to call, or where can I find the item name's whose define the variable you want to modify.
This is, I need to set this:
<style name="ColorTheme" parent="android:Theme.Black">
<item name="android:checkboxStyle">#style/CheckBoxColorTheme</item>
<item name="android:buttonStyle">#style/ButtonColorTheme</item>
<item name="android:imageButtonStyle">#style/ImageButtonColorTheme</item>
</style>
Inside of this:
<style name="Theme.CustomActionBarTheme" parent="#style/Theme.AppCompat">
<item name="actionBarItemBackground">#drawable/ab_selectable_background</item>
<item name="popupMenuStyle">#style/PopupMenu</item>
<item name="dropDownListViewStyle">#style/DropDownListView</item>
<item name="actionBarTabStyle">#style/ActionBarTabStyle</item>
<item name="actionDropDownStyle">#style/DropDownNav</item>
<item name="actionBarStyle">#style/ActionBar.Transparent</item>
<item name="actionModeBackground">#drawable/cab_background_top_customactionbartheme</item>
<item name="actionModeSplitBackground">#drawable/cab_background_bottom_customactionbartheme</item>
<item name="actionModeCloseButtonStyle">#style/ActionButton.CloseMode</item>
</style>

Maybe you need to do this?
<style name="ColorTheme" parent="Theme.CustomActionBarTheme">
<item name="android:checkboxStyle">#style/CheckBoxColorTheme</item>
<item name="android:buttonStyle">#style/ButtonColorTheme</item>
<item name="android:imageButtonStyle">#style/ImageButtonColorTheme</item>

can't change color of actionBar divider

I tried change color of my actionBar divider , but nothing work. I' using android support library v7 for support old devices and custom style, and i also change all action bar drawable, but nothing happend!
<resources>
<style name="MyTheme" parent="Theme.AppCompat">
<item name="actionBarStyle">#style/MyActionBar</item>
</style>
<style name="MyActionBar" parent = "Widget.AppCompat.ActionBar">
<item name="background">#drawable/my_action_bar</item>
</style>
</resources>
And my ide show me strange error in layout , why did i get this error? it's not color value
java.lang.NumberFormatException: Color value '#drawable/abs__ab_transparent_dark_holo' must start with #
Solution: Need to add android namespace if use for api level >= 14 .May be it will be helpful to someone.

It is because the "divider" is an image. It's hardcoded in the Holo theme assets.
Look at platforms/android-19/data/res/drawable-xxhdpi/ab_transparent_dark_holo.9.png
The style is declared here for holo dark.
<style name="Widget.Holo.ActionBar" parent="Widget.ActionBar">
...
<item name="android:background">#android:drawable/ab_transparent_dark_holo</item>
...
</style>
It's a background. You will need to change the color in the image and replace the background of your bar.
It also needs different sizes for different resolutions.

Maybe you should set color directly, change your theme as
<item name="android:divider">#color/dividercolor</item>
Then you should add color dividercolor in you /value/color file,like
<item name="dividercolor"> #0099CC </item>

I hope this will be helpful to you
<style name="CustomTheme" parent="#android:style/Theme.Holo.Light">
<item name="android:actionBarStyle">#style/MyTheme.ActionBarStyle</item>
<item name="android:actionBarDivider">#drawable/action_vertical_doted</item>
<item name="android:actionButtonStyle">#style/MyTheme.ActionBar.ActionButton</item>
<item name="android:actionMenuTextColor">#ffffff</item>
<!-- <item name="android:actionMenuTextAppearance">#style/MyTheme.Menu.FontStyle</item> -->
<!-- <item name="android:actionBarSize">50dp</item> -->
</style>
<style name="MyTheme.ActionBarStyle" parent="#android:style/Widget.Holo.Light.ActionBar">
<item name="android:titleTextStyle">#style/MyTheme.ActionBar.TitleTextStyle</item>
<item name="android:background">#drawable/actionbar_bg_shap</item>
<item name="android:displayOptions">none</item>
<item name="android:backgroundSplit">#drawable/actionbar_bg_shap</item>
</style>
<style name="MyTheme.ActionBar.ActionButton" parent="#android:style/Widget.Holo.Light.ActionButton">
<item name="android:background">#drawable/main_button_inactive_tr</item>
</style>

How to set custom ActionBar color / style?

I am using Android Navigation bar in my project,
I want to change the top color in action bar to something red, How can i do that?
I have something like this,
and i want something like this,
how can i achieve that?

You can define the color of the ActionBar (and other stuff) by creating a custom Style:
Simply edit the res/values/styles.xml file of your Android project.
For example like this:
<resources>
<style name="MyCustomTheme" parent="#android:style/Theme.Holo.Light">
<item name="android:actionBarStyle">#style/MyActionBarTheme</item>
</style>
<style name="MyActionBarTheme" parent="#android:style/Widget.Holo.Light.ActionBar">
<item name="android:background">ANY_HEX_COLOR_CODE</item>
</style>
</resources>
Then set "MyCustomTheme" as the Theme of your Activity that contains the ActionBar.
You can also set a color for the ActionBar like this:
ActionBar actionBar = getActionBar();
actionBar.setBackgroundDrawable(new ColorDrawable(Color.RED)); // set your desired color
Taken from here: How do I change the background color of the ActionBar of an ActionBarActivity using XML?

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:--
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
</style>
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
<style name="MyActionBar" parent="#style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
<item name="background">#color/red</item>
</style>
And this definition we need to reference in our AppTheme, pointing to overridden ActionBar styling as--
#style/MyActionBar
Change the title bar text color (e.g black to white):--
Now to change the title text color, we need to override the parent reference parent="#style/TextAppearance.AppCompat.Widget.ActionBar.Title">
So the style definition would be
<style name="MyActionBarTitle" parent="#style/TextAppearance.AppCompat.Widget.ActionBar.Title">
<item name="android:textColor">#color/white</item>
</style>
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
<style name="MyActionBar" parent="#style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
<item name="background">#color/red</item>
<item name="titleTextStyle">#style/MyActionBarTitle</item>
</style>
SO this is the final Styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light">
<!-- This is the styling for action bar -->
<item name="actionBarStyle">#style/MyActionBar</item>
</style>
<style name="MyActionBar" parent="#style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
<item name="background">#color/red</item>
<item name="titleTextStyle">#style/MyActionBarTitle</item>
</style>
<style name="MyActionBarTitle" parent="#style/TextAppearance.AppCompat.Widget.ActionBar.Title">
<item name="android:textColor">#color/white</item>
</style>
</resources>
For further ActionBar options Menu styling, refer this link

For Android 3.0 and higher only
When supporting Android 3.0 and higher only, you can define the action bar's background like this:
res/values/themes.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- the theme applied to the application or activity -->
<style name="CustomActionBarTheme" parent="#style/Theme.Holo.Light.DarkActionBar">
<item name="android:actionBarStyle">#style/MyActionBar</item>
</style>
<!-- ActionBar styles -->
<style name="MyActionBar" parent="#style/Widget.Holo.Light.ActionBar.Solid.Inverse">
<item name="android:background">#ff0000</item>
</style>
</resources>
For Android 2.1 and higher
When using the Support Library, your style XML file might look like this:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- the theme applied to the application or activity -->
<style name="CustomActionBarTheme" parent="#style/Theme.AppCompat.Light.DarkActionBar">
<item name="android:actionBarStyle">#style/MyActionBar</item>
<!-- Support library compatibility -->
<item name="actionBarStyle">#style/MyActionBar</item>
</style>
<!-- ActionBar styles -->
<style name="MyActionBar"
parent="#style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
<item name="android:background">#drawable/actionbar_background</item>
<!-- Support library compatibility -->
<item name="background">#drawable/actionbar_background</item>
</style>
</resources>
Then apply your theme to your entire app or individual activities:
for more details Documentaion

You can change action bar color on this way:
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="colorPrimary">#color/green_action_bar</item>
</style>
Thats all you need for changing action bar color.
Plus if you want to change the status bar color just add the line:
<item name="android:colorPrimaryDark">#color/green_dark_action_bar</item>
Here is a screenshot taken from developer android site to make it more clear, and here is a link to read more about customizing the color palete

Another possibility of making.
actionBar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#0000ff")));

I can change ActionBar text color by using titleTextColor
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="titleTextColor">#333333</item>
</style>

Custom Color:
<style name="AppTheme" parent="Theme.AppCompat.Light">
<item name="colorPrimary">#color/ColorPrimary</item>
<item name="colorPrimaryDark">#color/ColorPrimaryDark</item>
<!-- Customize your theme here. -->
</style>
Custom Style:
<style name="Theme.AndroidDevelopers" parent="android:style/Theme.Holo.Light">
<item name="android:selectableItemBackground">#drawable/ad_selectable_background</item>
<item name="android:popupMenuStyle">#style/MyPopupMenu</item>
<item name="android:dropDownListViewStyle">#style/MyDropDownListView</item>
<item name="android:actionBarTabStyle">#style/MyActionBarTabStyle</item>
<item name="android:actionDropDownStyle">#style/MyDropDownNav</item>
<item name="android:listChoiceIndicatorMultiple">#drawable/ad_btn_check_holo_light</item>
<item name="android:listChoiceIndicatorSingle">#drawable/ad_btn_radio_holo_light</item>
</style>
For More: Android ActionBar

As I was using AppCompatActivity above answers didn't worked for me. But the below solution worked:
In res/styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
</style>
PS: I've used colorPrimary instead of android:colorPrimary

in the style.xml add this code
<resources>
<style name="MyTheme" parent="#android:style/Theme.Holo.Light">
<item name="android:actionBarStyle">#style/MyAction</item>
</style>
<style name="MyActionBarTheme" parent="#android:style/Widget.Holo.Light.ActionBar">
<item name="android:background">#333333</item>
</style>
</resources>

Use this - http://jgilfelt.github.io/android-actionbarstylegenerator/
Good tool to customize your actionbar with a live preview in couple of minutes.