whatsapp_web_groups/project_semaphore/views/project_project_views.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <data>
        <!-- Inherit project kanban view to add semaphore ribbons -->
        <record id="project_project_kanban_semaphore" model="ir.ui.view">
            <field name="name">project.project.kanban.semaphore</field>
            <field name="model">project.project</field>
            <field name="inherit_id" ref="project.view_project_kanban"/>
            <field name="arch" type="xml">
                <xpath expr="//div[contains(@class,'o_project_kanban_main')]" position="before">
                    <!-- Red semaphore ribbon (color = 1) -->
                    <widget name="web_ribbon" 
                            title="⚠️" 
                            bg_color="text-bg-danger" 
                            invisible="color != 1"/>
                    
                    <!-- Green semaphore ribbon (color = 10) -->
                    <widget name="web_ribbon" 
                            title="👍" 
                            bg_color="text-bg-success" 
                            invisible="color != 10"/>
                    
                    <!-- Yellow semaphore ribbon (color = 3) -->
                    <widget name="web_ribbon" 
                            title="😐" 
                            bg_color="text-bg-warning" 
                            invisible="color != 3"/>
                </xpath>
            </field>
        </record>
    </data>
</odoo>