If Excel is not highlighting cells in the formula, enable 'Allow editing directly in cells' and 'Enable fill handle and cell drag-and-drop' in Excel options.

The default active cell format in Microsoft Excel isn't all that easy to see, but you can use this easy-to-implement code solution to change that.

How to Keep the Active Cell in Excel. Microsoft Excel 2013 surrounds the active cell with a dark border to help identify the cell you are editing. Pressing the Enter key after editing the cell ...

You find Excel's highlight function under the "Conditional Formatting" button in the Styles section under the Home tab. When you click it, a drop-down menu appears with a "Highlight Cell Rules ...