suite/website_project_task/project_task_templates.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

    <template id="my_tasks" inherit_id='project.portal_my_tasks' name="Stage Colors etc.">
        <xpath expr="//td/span[@class='label label-info']" position="attributes">
            <attribute name="t-attf-class">label label-info stage stage-{{ task.stage_id.name }}</attribute>
        </xpath>
    </template>


    <template id="task_tag_grid" inherit_id='project.portal_my_tasks' customize_show="True" name="Task Tags on table">
        <xpath expr="//table/thead/tr/th[1]" position="attributes">
            <attribute name="class">col-md-8</attribute>
        </xpath>
        <xpath expr="//table/thead/tr/th[2]" position="after">
            <th>Tags</th>
        </xpath>
        <!-- Strange number of columns -->
        <xpath expr="//table/tbody/t/tr/td[1]" position="after">
            <td>
                <t t-foreach="task.tag_ids" t-as="tag">
                    <span t-attf-class="label tag tag-color-{{ tag.color }} tag-{{ tag.name }}"><t t-esc="tag.name"/></span>
                </t>
            </td>
        </xpath>
    </template>

    <template id="my_task" inherit_id='project.portal_my_task' name="Stage Colors etc.">
        <xpath expr="//span[@class='pull-right label label-info']" position="attributes">
            <attribute name="t-attf-class">pull-right label label-info stage stage-{{ task.stage_id.name }}</attribute>
        </xpath>
        <xpath expr="//h4" position="after">
            <p t-if="task.tag_ids">
                <span t-foreach="task.tag_ids" t-as="tag" t-attf-class="label tag tag-color-{{ tag.color }} tag-{{ tag.name }}" t-field="tag.name" />
            </p>
        </xpath>
    </template>

</odoo>