How to fix background red color TextInputLayout when isEmpty in Android

You can subclass TextInputLayout and use that:

package com.mypackage;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.support.annotation.Nullable;
import android.support.design.widget.TextInputLayout;
import android.util.AttributeSet;

public class CustomTextInputLayout extends TextInputLayout {
    public CustomTextInputLayout(Context context) {
        super(context);
    }

    public CustomTextInputLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomTextInputLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void drawableStateChanged() {
        super.drawableStateChanged();
        clearEditTextColorfilter();
    }
    @Override
    public void setError(@Nullable CharSequence error) {
        super.setError(error);
        clearEditTextColorfilter();
    }

    private void clearEditTextColorfilter() {
        EditText editText = getEditText();
        if (editText != null) {
            Drawable background = editText.getBackground();
            if (background != null) {
                background.clearColorFilter();
            }
        }
    }
}

in your layout:

<com.mypackage.CustomTextInputLayout
    android:id="@+id/register_userUsernameTextLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/register_headerLayout"
    android:layout_margin="10dp"
    android:textColorHint="#c5c5c5">

    <EditText
        android:id="@+id/register_userUserNameText"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:background="@drawable/selector_bg_edit"
        android:hint="نام کاربری"
        android:paddingBottom="2dp"
        android:textColor="@color/colorAccent"
        android:textCursorDrawable="@drawable/bg_input_cursor"
        android:textSize="16sp" />
</android.support.design.widget.TextInputLayout>

in my case I added line

<solid android:color="@color/transparent"/>

<shape android:shape="rectangle"
xmlns:android="http://schemas.android.com/apk/res/android" >
    <stroke android:color="@color/lightGray" android:width="1dp"/>
    <solid android:color="@color/transparent"/>
    <padding android:top="7dp" android:bottom="7dp" android:left="7dp" android:right="7dp"/>
    <corners android:radius="2dp"/>
</shape>

this results in red border only not entire background

I have found a workaround to this problem. You just need to create a custom EditText and override the getBackground() method of it to return a new drawable. That way TextInputLayout won't be able to set color filter on the EditText's background, since you do not return EditText's background, but some another drawable. See below:

@Override
public Drawable getBackground() {
    return ContextCompat.getDrawable(getContext(), R.drawable.some_drawable);
}

and use the custom EditText inside TextInputLayout:

<android.support.design.widget.TextInputLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

        <CustomEditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@drawable/custom_edit_text_bg" />

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