[FIX] project: set the default color in the project app

Description of the issue/feature this PR addresses:

-In the project module when the calendar view of a task is open click on any
  schedule, and popover is open.
-In popover tags colors are not visible

Current behavior before PR:
In the popover, tag field colors are not visible

Desired behavior after PR is merged:
tags colors are visible when opening the popover

Fix:
  we add options attribute in the many2many_tags widget.

task-3269548

closes odoo/odoo#120996

Signed-off-by: Xavier Bol (xbo) <xbo@odoo.com>

addons/project/views/project_views.xml

@@ -1587,7 +1587,7 @@
                     <field name="partner_id" attrs="{'invisible': [('partner_id', '=', False)]}"/>
                     <field name="priority" widget="priority"/>
                     <field name="date_deadline"/>
-                    <field name="tag_ids" widget="many2many_tags" attrs="{'invisible': [('tag_ids', '=', [])]}"/>
+                    <field name="tag_ids" widget="many2many_tags" options="{'color_field': 'color'}" attrs="{'invisible': [('tag_ids', '=', [])]}"/>
                     <field name="stage_id"/>
                     <field name="kanban_state"/>
                 </calendar>