I want to create a tree viewww with colors for each states but the following errors is occured :

Uncaught Error: QWeb2 - template['ListView.rows']: Runtime Error: Error: QWeb2 - template['ListView.row']: Runtime Error: Error: NameError: name 'state' is not defined

this is my XML code:

 <header>
                        <button string="Confirmer Programme" name="button_confirm" states="draft" type="object" class="oe_highlight" groups="base.group_user"/>
                        <button string="Gagner Programme" name="button_done" states="confirm" type="object" class="oe_highlight" groups="base.group_user"/>
                        <button string="Unconfirmer Programme" name="button_draft" states="cancel,done" type="object" groups="base.group_user"/>
                        <button string="Annuler Programme" name="button_cancel" states="draft,confirm" type="object" groups="base.group_user"/>
                        <field name="state" widget="statusbar" statusbar_visible="draft,confirm,done" statusbar_colors='{"draft":"blue"}'/>
                    </header>

this is my tree view

<record model="ir.ui.view" id="programme_tree">
        <field name="name">programme.tree</field>
        <field name="model">programme</field>
        <field name="type">tree</field> 
        <field name="arch" type="xml">
            <tree colors="blue:state == 'draft';red:state =='confirm';gray:state == 'cancel'" string="Formulaire programme" >
                
                <field name="date_fin"/>
                <field name="date_resultat"/>
                <field name="nb__notif"/>
                <field name="prog_condition"/>
            </tree>
        </field>
    </record>

Please someone help me