我解决了问题。 这是布局:

 <android.support.design.widget.TextInputLayout
           android:id="@+id/til_username"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:hint="@string/username"
           >

           <android.support.v7.widget.AppCompatEditText android:id="@+id/et_username"
               android:layout_width="match_parent"
               android:layout_height="wrap_content"
               android:singleLine="true"
               />
       </android.support.design.widget.TextInputLayout>

这就是风格:

<style name="AppBaseTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!--
            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        -->
    </style>
<!-- Application theme. -->


 <style name="AppTheme" parent="AppBaseTheme">
        <!-- All customizations that are NOT specific to a particular API-level can go here. -->
        <item name="colorAccent">@color/pink</item>
        <item name="colorControlNormal">@color/purple</item>
        <item name="colorControlActivated">@color/yellow</item>
    </style>

你应该在应用程序中使用你的主题:

<application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
</application>

更改提示颜色和编辑文本下划线颜色:colorControlActivated

更改字符计数器颜色:textColorSecondary

更改错误信息的颜色:colorControlNormal

要更改密码可见性按钮颜色:colorForeground

更多关于TextInputLayout的信息请阅读http://www.zoftino.com/android-textinputlayout-tutorial

<style name="MyAppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorControlActivated">#e91e63</item>
    <item name="android:colorForeground">#33691e</item>
    <item name="colorControlNormal">#f57f17</item>
    <item name="android:textColorSecondary">#673ab7</item>
</style>

好的，所以，我发现这个答案非常有用，感谢所有贡献的人。只是补充一点。公认的答案确实是正确的答案…但是…在我的情况下，我正在寻找实现下面的错误消息EditText小部件与app: errorrenabled ="true"和这一行使我的生活困难。似乎这覆盖了我为android.support.design.widget. textinputlayout选择的主题，它有一个由android:textColorPrimary定义的不同的文本颜色。

最后，我将文本颜色直接应用到EditText小部件上。我的代码是这样的:

styles.xml

<item name="colorPrimary">@color/my_yellow</item>
<item name="colorPrimaryDark">@color/my_yellow_dark</item>
<item name="colorAccent">@color/my_yellow_dark</item>
<item name="android:textColorPrimary">@android:color/white</item>
<item name="android:textColorSecondary">@color/dark_gray</item>
<item name="android:windowBackground">@color/light_gray</item>
<item name="windowNoTitle">true</item>
<item name="windowActionBar">false</item>
<item name="android:textColorHint">@color/dark_gray</item>
<item name="android:colorControlNormal">@android:color/black</item>
<item name="android:colorControlActivated">@android:color/white</item>

我的小部件:

<android.support.design.widget.TextInputLayout
        android:id="@+id/log_in_layout_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:errorEnabled="true">

        <EditText
            android:id="@+id/log_in_name"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:textColor="@android:color/black"
            android:ems="10"
            android:hint="@string/log_in_name"
            android:inputType="textPersonName" />
</android.support.design.widget.TextInputLayout>

现在它显示黑色文本颜色而不是textColorPrimary白色。

你应该换一下颜色

<style name="Base.Theme.DesignDemo" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="colorPrimary">#673AB7</item>
        <item name="colorPrimaryDark">#512DA8</item>
        <item name="colorAccent">#FF4081</item>
        <item name="android:windowBackground">@color/window_background</item>
    </style>

因为你必须在主应用主题中添加colorControlNormal, colorControlActivated, colorControlHighLight三项:

<!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">

        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>

        <item name="colorControlActivated">@color/yellow_bright</item>
        <item name="colorControlNormal">@color/yellow_black</item>

    </style>

我如何改变浮动标签文本颜色?

使用材质组件库，您可以自定义TextInputLayout提示文本颜色使用(它需要版本1.1.0)

在布局中: app:hintTextColor属性:标签折叠和文本字段激活时的颜色 android:textColorHint属性:标签的颜色在所有其他文本字段的状态(如休息和禁用)

<com.google.android.material.textfield.TextInputLayout
     app:hintTextColor="@color/mycolor"
     android:textColorHint="@color/text_input_hint_selector"
     .../>

扩展材质样式Widget.MaterialComponents.TextInputLayout.*:

<style name="MyFilledBox" parent="Widget.MaterialComponents.TextInputLayout.FilledBox">
    <item name="hintTextColor">@color/mycolor</item>
    <item name="android:textColorHint">@color/text_input_hint_selector</item>
</style>

android:textColorHint的默认选择器是:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:alpha="0.38" android:color="?attr/colorOnSurface" android:state_enabled="false"/>
  <item android:alpha="0.6" android:color="?attr/colorOnSurface"/>
</selector>