[IMP] note: add default random color in tag

Currently, when we creating a tag, it does not appear in the Kanban
view because the tag does not have a default color. 

This commit solve above problem by adding default random color in tag.

task-3089296

closes odoo/odoo#107800

Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

addons/note/models/note.py

@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
+from random import randint
+
 from odoo import api, fields, models, _
 from odoo.tools import html2plaintext
 
@@ -22,8 +24,11 @@ class Tag(models.Model):
     _name = "note.tag"
     _description = "Note Tag"
 
+    def _get_default_color(self):
+        return randint(1, 11)
+
     name = fields.Char('Tag Name', required=True, translate=True)
-    color = fields.Integer('Color Index')
+    color = fields.Integer('Color Index', default=_get_default_color)
 
     _sql_constraints = [
         ('name_uniq', 'unique (name)', "Tag name already exists !"),