ui/android/java/res/drawable/color_picker_border.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2013 The Chromium Authors. All rights reserved.
     Use of this source code is governed by a BSD-style license that can be
     found in the LICENSE file.
-->

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <stroke android:width="1px" android:color="@color/color_picker_border_color" />
    <solid android:color="@color/color_picker_background_color"/>
</shape>