<com.google.android.material.textfield.TextInputLayout
    android:hint="Hint"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/TextInputLayoutHint">

    <androidx.appcompat.widget.AppCompatEditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="text"
        android:maxLines="1"
        android:paddingTop="@dimen/_5sdp"
        android:paddingBottom="@dimen/_5sdp"
        android:textColor="#000000"
        android:textColorHint="#959aa6" />

</com.google.android.material.textfield.TextInputLayout>

res /价值/ styles.xml

<style name="TextInputLayoutHint" parent="">
    <item name="android:textColorHint">#545454</item>
    <item name="colorControlActivated">#2dbc99</item>
    <item name="android:textSize">11sp</item>
</style>

我建议你为TextInputLayout做风格主题，只改变强调色。设置父主题为你的应用程序基础主题:

 <style name="MyTextInputLayout" parent="MyAppThemeBase">
     <item name="colorAccent">@color/colorPrimary</item>
 </style>

 <android.support.design.widget.TextInputLayout
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:theme="@style/MyTextInputLayout">

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>

在我的情况下，我添加了这个“app:hintTextAppearance=“@color/colorPrimaryDark”在我的TextInputLayout小部件。

如果你使用com.google.android.material.textfield，可以使用app:hintTextColor。TextInputLayout，试试这个

 <com.google.android.material.textfield.TextInputLayout
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:hint="@string/app_name" 
     app:hintTextColor="@android:color/white">                   

     <com.google.android.material.textfield.TextInputEditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />
 </com.google.android.material.textfield.TextInputLayout>

在最新版本的支持库(23.0.0+)中，TextInputLayout采用以下XML属性来编辑浮动标签颜色: