Let us see how to customize the footer menu colours.

Go to Site & Pages. Click Edit button.

Go to Footer Menu & click Settings. Go to Style Tab.

We can change all style aspects here. You can change the background colour, text colour, link colour, link hover colour, button colour, button text colour, button border colour, button hover colour, and button hover text colour. We can also make this full width.

Make desired changes & click Save. Click Preview to see the colour changes in your footer.

Please note that you can also change the footer menu styling under Branding in the site. Check out the support docs on Branding.