design-themes/theme_artists/views/snippets/s_process_steps.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

<template id="s_process_steps" inherit_id="website.s_process_steps">
    <!-- Section -->
    <xpath expr="//section" position="attributes">
        <attribute name="class" add="o_cc o_cc3" separator=" "/>
    </xpath>
    <!-- Icons -->
    <xpath expr="//i" position="attributes">
        <attribute name="class" add="bg-o-color-5" remove="bg-o-color-1" separator=" "/>
    </xpath>
    <xpath expr="(//i)[3]" position="attributes">
        <attribute name="class" add="bg-o-color-5" remove="bg-o-color-2" separator=" "/>
    </xpath>
    <xpath expr="(//i)[4]" position="attributes">
        <attribute name="class" add="bg-o-color-5" remove="bg-o-color-3" separator=" "/>
    </xpath>
</template>

</odoo>