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>

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>

这很简单，但由于多个视图在不同的配置/名称空间中具有相同的属性，开发人员会感到困惑。

在TextInputLayout的情况下，我们每次都有一个不同的视图和参数，要么与TextInputEditText或直接到TextInputLayout。

我使用了以上所有的修复: 但我发现我在吸毒

                app:textColorHint="@color/textcolor_black"

其实我应该用

                android:textColorHint="@color/textcolor_black"

作为TextinputLayout的属性

textcolor_black.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="@color/black_txt" android:state_enabled="true" />
    <item android:color="@color/black_txt" android:state_selected="true" />
    <item android:color="@color/txtColorGray" android:state_selected="false" />
    <item android:color="@color/txtColorGray" android:state_enabled="false" />
</selector>

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>

你可以在程序上使用:

/* Here you get int representation of an HTML color resources */
int yourColorWhenEnabled = ContextCompat.getColor(getContext(), R.color.your_color_enabled);
int yourColorWhenDisabled = ContextCompat.getColor(getContext(), R.color.your_color_disabled);

/* Here you get matrix of states, I suppose it is a matrix because using a matrix you can set the same color (you have an array of colors) for different states in the same array */
int[][] states = new int[][]{new int[]{android.R.attr.state_enabled}, new int[]{-android.R.attr.state_enabled}};

/* You pass a ColorStateList instance to "setDefaultHintTextColor" method, remember that you have a matrix for the states of the view and an array for the colors. So the color in position "colors[0x0]" will be used for every states inside the array in the same position inside the matrix "states", so in the array "states[0x0]". So you have "colors[pos] -> states[pos]", or "colors[pos] -> color used for every states inside the array of view states -> states[pos] */
myTextInputLayout.setDefaultHintTextColor(new ColorStateList(states, new int[]{yourColorWhenEnabled, yourColorWhenDisabled})

解释:

Get int color value from a color resource (a way to present rgb colors used by android). I wrote ColorEnabled, but really it should be, for this answer, ColorHintExpanded & ColorViewCollapsed. Anyway this is the color you will see when the hint of a view "TextInputLayout" is on Expanded or Collapsed state; you will set it by using next array on function "setDefaultHintTextColor" of the view. Reference: Reference for TextInputLayout - search in this page the method "setDefaultHintTextColor" for more info

查看上面的文档，你可以看到函数通过使用ColorStateList来设置展开和折叠提示的颜色。

ColorStateList docs

To create the ColorStateList I first created a matrix with the states I want, in my case state_enabled & state_disabled (whose are, in TextInputLayout, equals to Hint Expanded and Hint Collapsed [I don't remember in which order lol, anyway I found it just doing a test]). Then I pass to the constructor of the ColorStateList the arrays with int values of color resources, these colors have a correspondences with the states matrix (every element in colors array correspond to the respective array in states matrix at same position). So the first element of the colors array will be used as color for every state in the first array of the states matrix (in our case the array has only 1 element: enabled state = hint expanded state for TextInputLayut). Last things states have positive / negative values, and you have only the positive values, so the state "disabled" in android attrs is "-android.state.enabled", the state "not focused" is "-android.state.focused" ecc.. ecc..

希望这对你有帮助。 再见，祝你编码愉快。

现在，简单地使用colorAccent和colorPrimary就可以完美地工作了。