Based on Fedor Kazakov and others answers, I created a default config.
styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
<style name="Widget.Design.TextInputLayout" parent="AppTheme">
<item name="hintTextAppearance">@style/AppTheme.TextFloatLabelAppearance</item>
<item name="errorTextAppearance">@style/AppTheme.TextErrorAppearance</item>
<item name="counterTextAppearance">@style/TextAppearance.Design.Counter</item>
<item name="counterOverflowTextAppearance">@style/TextAppearance.Design.Counter.Overflow</item>
</style>
<style name="AppTheme.TextFloatLabelAppearance" parent="TextAppearance.Design.Hint">
<!-- Floating label appearance here -->
<item name="android:textColor">@color/colorAccent</item>
<item name="android:textSize">20sp</item>
</style>
<style name="AppTheme.TextErrorAppearance" parent="TextAppearance.Design.Error">
<!-- Error message appearance here -->
<item name="android:textColor">#ff0000</item>
<item name="android:textSize">20sp</item>
</style>
</resources>
activity_layout.xml
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.AppCompatEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Text hint here"
android:text="5,2" />
</android.support.design.widget.TextInputLayout>
Focused:
Without focus:
Error message: