Hi,
thanks for the file! I did receive it and had a quick look.
Unfortunately, I can’t offer a directly usable solution to highlight those cells based on the current date in different colors automatically.
However, I can point you to a few resources that might help in developing a custom solution:
There is a TablePress Extension to highlight cells based on static table data, with more information available at https://tablepress.org/download/extension/tablepress-cell-highlighting.zip (For details and an example, please see the PHP file source code, which has one in the comment at the top.)
In addition, there’s a TablePress Extension that can be used to filter out (hide) table rows that contain dates in the past or future, see https://tablepress.org/download/extension/tablepress-row-filter-date.zip (instructions in the PHP file again).
You could maybe take ideas and code from this to adjust the first Extension to achieve what you need.
Regards,
Tobias