Take a look at the formula definition for the {due back} field in the [out] table of my Wardrobe Manager base in Airtable universe. In it, I return the due date without special formatting if the date is 2 or more days from today, formatted with an ‘alert’ setting if the due date is today or tomorrow, and formatted with a ‘high alert’ setting if the due date has already passed. You should be able to splice it into your base with minimal effort.
BTW, if you simply want to see how that formula works without having to copy the entire base, select ‘Explore the base’ from its Universe page. Scroll down until you get to the [out] table and select ‘Developer view (all fields).’ Scroll horizontally through the entire table; {due back} is the last field defined. Hover your cursor over the ‘i-in-a-circle’ ‘information’ icon at the end of the field definition. For [almost] every field in Wardrobe Manager, the field description contains an explanation of the field and, if a formula field, the full text of the formula.
