web/web_company_color/view/res_company.xml

<?xml version="1.0"?>

<!--
    Copyright 2019
    @author Alexandre Díaz <dev@redneboa.es>
    License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
-->

<odoo>

    <record id="view_company_form" model="ir.ui.view">
        <field name="model">res.company</field>
        <field name="inherit_id" ref="base.view_company_form" />
        <field name="arch" type="xml">
            <notebook position="inside">
                <page string="Company Styles" name="company_styles"
                      groups="base.group_system">
                    <group string="Navbar Colors" name="navbar_colors">
                        <field name="color_navbar_bg" widget="color" />
                        <field name="color_navbar_bg_hover" widget="color" />
                        <field name="color_navbar_text" widget="color" />
                    </group>
                    <div class="alert alert-info info_icon" role="alert">
                        <span class="fa fa-info fa-2x" />
                        In order for the changes to take effect, please refresh
                        the page.
                    </div>
                </page>
            </notebook>
        </field>
    </record>

</odoo>