Formula Required: What is the best way to achieve the following?

What is the best way to achieve the following? I’ve attached a part sample of the spreadsheet for reference.
In this example I want to compare cells B2, B3, B8 & B9 together and B4, B5, B6 & B7. If the difference between any of the cells is greater than 5 but less than 10 then the cell(s) containing the higher value changes to orange. If the value is 10 or more then the cell(s) change to red.
Additionally, I would like a pop up message to appear for each highlighted cell which could then be acknowledged. (Possibly a different thread?)
Each column would be entered daily/weekly with only the column reference changing.
Any help would be greatly appreciated.