ActionBar ID不是直接可用的，所以你必须做一点hack。

int actionBarTitleId = Resources.getSystem().getIdentifier("action_bar_title", "id", "android");
if (actionBarTitleId > 0) {
    TextView title = (TextView) findViewById(actionBarTitleId);
    if (title != null) {
        title.setTextColor(Color.RED);
    }
}

<android.support.v7.widget.Toolbar
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:id="@+id/toolbar"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:background="@color/color_primary"
  android:theme="@style/GalaxyZooThemeToolbarDarkOverflow"
  app:popupTheme="@style/Theme.AppCompat.NoActionBar" />


<style name="GalaxyZooThemeToolbarDarkOverflow" parent="Theme.AppCompat.NoActionBar">
  <!-- android:textColorPrimary is the  color of the title text
       in the Toolbar, in the Theme.AppCompat theme:  -->
  <item name="android:textColorPrimary">@color/abc_primary_text_material_light</item>
 
  <!-- android:textColorPrimaryInverse is the  color of the title
       text in the Toolbar, in the Theme.AppCompat.Light theme:  -->
  <!-- <item name="android:textColorPrimaryInverse">@color/abc_primary_text_material_light</item> -->
 
  <!-- android:actionMenuTextColor is the color of the text of
        action (menu) items in the Toolbar, at least in the
        Theme.AppCompat theme.
        For some reason, they already get the textColorPrimary
        when running on API 21, but not on older versions of
        Android, so this is only necessary to support older
        Android versions.-->
        <item name="actionMenuTextColor">@color/abc_primary_text_material_light</item>
  <!-- android:textColorSecondary is the color of the menu
       overflow icon (three vertical dots) -->
  <item name="android:textColorSecondary">@color/abc_secondary_text_material_light</item>
 
  <!-- This would set the toolbar's background color,
        but setting this also changes the popup menu's background,
        even if we define popupTheme for our <Toolbar> -->
  <!-- <item name="android:background">@color/color_primary</item> -->
</style>


**Reference:**
[https://www.murrayc.com/permalink/2014/10/28/android-changing-the-toolbars-text-color-and-overflow-icon-color/][1]

就我而言，我切换到AndroidX工具栏，而不是使用本机操作栏。此外，我依赖于视图绑定从活动访问工具栏，但您可以使用findViewById(…)。

(我删除了不相关的代码)。

styles.xml:

...
<style name="AppTheme" parent="Theme.MaterialComponents.Light.NoActionBar">
  ...
</style>
...

activity_main.xml:

...
<androidx.appcompat.widget.Toolbar
  android:id="@+id/toolbarMain"
  android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
  app:titleTextColor="@color/colorOnPrimary"
  ...
/>
...

MainActivity.kt:

class MainActivity : AppCompatActivity() {

  private lateinit var binding: ActivityMainBinding
  ...

  override fun onCreate(savedInstanceState: Bundle?) {
    ...
    binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
    setSupportActionBar(binding.toolbarMain)
    ...
  }

  ...
}

将它添加到操作栏的根。我有这个问题。

<style name="ActionBar" parent="@style/Theme.AppCompat.Light">
    <item name="actionBarStyle">@style/Widget.Styled.ActionBar</item>
    <item name="actionMenuTextColor">@color/stdDarkBlueText</item>
</style>

<style name="Widget.Styled.ActionBar" parent="@style/Widget.AppCompat.Light.ActionBar">
    <item name="titleTextStyle">@style/ActionBarTitleText</item>
    <item name="subtitleTextStyle">@style/ActionBarSubTitleText</item>
</style>

<style name="ActionBarTitleText" parent="@style/TextAppearance.AppCompat.Widget.ActionBar.Title">
    <item name="android:textColor">@color/stdDarkBlueText</item>
    <item name="android:textSize">12sp</item>
</style>

<style name="ActionBarSubTitleText" parent="@style/TextAppearance.AppCompat.Widget.ActionBar.Subtitle">
    <item name="android:textColor">@color/stdDarkBlueText</item>
    <item name="android:textSize">12sp</item>
</style>

actionMenuTextColor -更改操作栏文本的颜色，当它是Widget.Styled的一部分时，它从未工作过。ActionBar，所以我必须把它添加到根目录中。其他2个属性更改操作栏的标题和副标题。

这是我检查所有答案后使用的解决方案

<!-- Base application theme. -->
<style name="AppTheme" parent="@style/Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorAccent">@color/Button_color</item>
    <item name="android:editTextStyle">@style/EditTextStyle</item>
    <item name="android:typeface">monospace</item>
    <item name="android:windowActionBar">true</item>
    <item name="colorPrimary">@color/Title_Bar_Color</item>
    <item name="android:actionBarStyle">@style/Widget.Styled.ActionBar</item>
    <item name="actionBarStyle">@style/Widget.Styled.ActionBar</item>

</style>

<style name="EditTextStyle" parent="Widget.AppCompat.EditText"/>

<style name="Widget.Styled.ActionBar" parent="@style/Widget.AppCompat.Light.ActionBar">
    <item name="titleTextStyle">@style/ActionBarTitleText</item>
    <item name="android:background">@color/Title_Bar_Color</item>
    <item name="background">@color/Title_Bar_Color</item>
    <item name="subtitleTextStyle">@style/ActionBarSubTitleText</item>
</style>

<style name="ActionBarTitleText" parent="@style/TextAppearance.AppCompat.Widget.ActionBar.Title">
    <item name="android:textColor">@color/solid_white</item>
    <item name="android:textSize">12sp</item>
</style>

<style name="ActionBarSubTitleText" parent="@style/TextAppearance.AppCompat.Widget.ActionBar.Subtitle">
    <item name="android:textColor">@color/solid_white</item>
    <item name="android:textSize">12sp</item>
</style>

改变所需的颜色就可以了

如果你想样式的字幕，然后简单地添加这在您的自定义样式。

<item name="android:subtitleTextStyle">@style/MyTheme.ActionBar.TitleTextStyle</item>

如果有人想在AppCompat库中得到同样的结果，那么这就是我所使用的:

<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="CustomActivityTheme" parent="@style/Theme.AppCompat.Light.DarkActionBar">
        <item name="android:actionBarStyle">@style/MyActionBar</item>
        <item name="actionBarStyle">@style/MyActionBar</item>
        <!-- other activity and action bar styles here -->
    </style>

    <!-- style for the action bar backgrounds -->
    <style name="MyActionBar" parent="Theme.AppCompat.Light.DarkActionBar">
        <item name="android:background">@drawable/actionbar_background</item>
        <item name="background">@drawable/actionbar_background</item>
        <item name="android:titleTextStyle">@style/MyTheme.ActionBar.TitleTextStyle</item>
        <item name="android:subtitleTextStyle">@style/MyTheme.ActionBar.TitleTextStyle</item>
        <item name="titleTextStyle">@style/MyTheme.ActionBar.TitleTextStyle</item>
        <item name="subtitleTextStyle">@style/MyTheme.ActionBar.TitleTextStyle</item>
     </style>
    <style name="MyTheme.ActionBar.TitleTextStyle" parent="@style/TextAppearance.AppCompat.Widget.ActionBar.Title">
        <item name="android:textColor">@color/color_title</item>
      </style>
</resources>