我尝试使用android:textColorHint在android.support.design.widget. textinputlayout它工作得很好。

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColorHint="@color/colorAccent">

            <EditText
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Hello"
                android:imeActionLabel="Hello"
                android:imeOptions="actionUnspecified"
                android:maxLines="1"
                android:singleLine="true"/>

        </android.support.design.widget.TextInputLayout>

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">

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>

<style name="TextAppearance.App.TextInputLayout" parent="@android:style/TextAppearance">
    <item name="android:textColor">@color/red</item>
    <item name="android:textSize">14sp</item>
</style>

<android.support.design.widget.TextInputLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textColorHint="@color/gray"  //support 23.0.0
    app:hintTextAppearance="@style/TextAppearence.App.TextInputLayout" >

    <android.support.v7.widget.AppCompatEditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/hint" />
</android.support.design.widget.TextInputLayout>

它为我工作..... 在TextInputLayout中添加提示颜色

    <android.support.design.widget.TextInputLayout
        android:textColorHint="#ffffff"
        android:id="@+id/input_layout_password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <EditText
            android:id="@+id/edtTextPassword"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="15dp"
            android:hint="Password"
            android:inputType="textPassword"
            android:singleLine="true"
            />
    </android.support.design.widget.TextInputLayout>

你不需要使用android:theme="@style/TextInputLayoutTheme"来改变浮动标签的颜色，因为它会影响到整个主题的小TextView用作标签。相反，你可以使用app:hintTextAppearance="@style/TextInputLayout。HintText”:

<style name="TextInputLayout.HintText">
  <item name="android:textColor">?attr/colorPrimary</item>
  <item name="android:textSize">@dimen/text_tiny_size</item>
  ...
</style>

让我知道解决方案是否有效:-)