chromium/android_webview/tools/system_webview_shell/apk/res/values-night/colors.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2019 The Chromium Authors
     Use of this source code is governed by a BSD-style license that can be
     found in the LICENSE file. -->

<resources>
    <color name="url_color">#F2F2F2</color>
    <color name="url_error_color">#F20000</color>
</resources>