design-themes/theme_common/views/s_blockquote.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <template name="Blockquote" id="s_blockquote">
        <blockquote class="s_blockquote blockquote">
            <i class="fa fa-quote-left fa-1x bg-beta rounded-0 s_blockquote_icon"/>
            <div class="s_blockquote_content" style="background-color: rgba(239,239,239);">
                <p>Write a quote here from one of your customers. Quotes are a great way to build confidence in your products or services.</p>
                <footer class="blockquote-footer">
                    <img class="img rounded-circle mr-2" src="/web/image/theme_common.image_content_10" alt=""/>
                    John DOE • CEO of MyCompany
                </footer>
            </div>
        </blockquote>
    </template>
</odoo>