Individual fields can’t be colored. If your base is in a Pro level workspace (or greater), you can use record coloring, which adds a colored marker to the left edge of the record (in a grid view). This can be set to use a condition similar to filtering, so you can color the record if that date field matches today’s date.
Adding an emoji is definitely an option, but I wouldn’t recommend doing it in the same field. Right now your calculation is outputting a date. To add more text (including emoji) to that same field with the date, and have that text based on the date, will require a much uglier formula, in part because you’re calculating the same date in multiple places. I’m all about keeping things clean and eliminating duplicated calculations if possible, so I suggest using two fields: your current one to calculate the due date (I’ll use {Due Date} for the field name), and another to add the emoji.
The formula I’m using for {Date + Emoji} is:
IF(IS_SAME({Due Date}, TODAY()), "⚠️ ") & DATETIME_FORMAT({Due Date}, "L")
In the end, you’d hide your current field and just leave the one with the optional emoji visible.
