There is always a default background on TextInputLayout in Android
https://github.com/material-components/material-components-android/issues/102
It seems a material textfield bug.
You can use this code to change background white temporarily.
<com.google.android.material.textfield.TextInputLayout
app:boxBackgroundColor="@android:color/transparent"
android:background="@android:color/transparent">
<com.google.android.material.textfield.TextInputEditText/>
</com.google.android.material.textfield.TextInputLayout>
One way to remove the background color is to adjust the background mode of TextInputLayout.
app:boxBackgroundMode="none"
Worked for me.
Example XML Code:
<com.google.android.material.textfield.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:boxBackgroundMode="none"
app:errorEnabled="true"
app:hintEnabled="false"
app:layout_constraintTop_toTopOf="parent">
<com.google.android.material.textfield.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="top"
android:hint="@string/comment_placeholder"
android:inputType="textCapSentences|textMultiLine"
android:maxLength="500" />
</com.google.android.material.textfield.TextInputLayout>
Method A
(completely transparent background)
<com.google.android.material.textfield.TextInputLayout
app:boxBackgroundMode="filled"
app:boxBackgroundColor="@null"
..>
<com.google.android.material.textfield.TextInputEditText
android:backgroundTint="@android:color/transparent"
..>
Method B
(solid background colour)
<com.google.android.material.textfield.TextInputLayout
app:boxBackgroundMode="filled"
app:boxBackgroundColor="?android:attr/colorBackground"
..>
*For my case, I needed it to be fully transparent as the screen background is not a solid colour. If that's the case for you, go with Method A