Hi,

I created a new Many2one field called grade on the stock.lot model. The grade model contains several fields, one of which is a color field:

color = fields.Integer(string="Color")

My goal is to display serial numbers with different colors in the picking view.

I tried to modify the many2many_tags widget in stock.view_picking_form using XPath to add a color_field option:

<xpath expr="//field[@name='lot_ids']" position="attributes">
    <attribute name="options">
        {'create': [('parent.use_create_lots', '=', True)], 'color_field': 'product_grade_id.color'}
    </attribute>
</xpath>

However, it seems many2many_tags cannot access a child field (product_grade_id.color) directly.

As a workaround I added a related field on stock.lot that copies the grade color:

grade_color = fields.Integer(
    related="product_grade_id.color",
    string="Grade color",
    readonly=True,
)

This works, but feels like a workaround. Is there a way to make many2many_tags use the child field directly, or a better pattern to achieve colored serial numbers in the picking view?

Thanks in advance for any suggestions.