Numbers Formula Help - Date Range Lookup & Highlight Cell With A Constraint

Hi guys,

Would really appreciate some help with creating a numbers formula as I can't get mine to work.

See screenshot of example table below which contains random dates.

I'm looking for a formula that will highlight all the cells (e.g. in yellow) if ANY of 3 or more of the dates within the entire table are within 3 weeks (21 days) of each other. (I have manually highlighted the cells in yellow as an example)

If another set of 3 or more different dates are also within 3 weeks of each other I would like all the applicable cells to be highlighted a different colour (e.g. in red). (I have manually highlighted the cells in red as an example)

The purpose of me needing this formula is because I have a much much bigger table that has dates that are updated every week which I need to highlight 3 or more dates which are all within 21 days of eachother. As you can imgine this is a very taxing and long process when trying to do it manually by eye.

Any help or suggestions would be great.

Cheers Nick