Highlight cell if value is different from the preceding cell-CodePudding

I'm have a number of columns (A / B / A / B / A / B etc) and I want the cells from column A to highlight if they are different from the cell in the preceding column A in the same row. And the same for columns B.

If the cell in the preceding column is empty, I don't want the cell to get highlighted.

This is what I want to achieve

I tried this in Google Sheets (range F4:M22) and then Custom Formula, which comes somewhat close, but not quite:

=IF(F4="","",F4<>H4)

If feel like there should be a simple solution, but I've been going around in circles. Any help much appreciated.

CodePudding user response：

Select all columns except the first and second one. Create a conditionnal formating with

=C1<>A1