Highlight Duplicates from Selection

This macro will check each cell of your selection and highlight the duplicate values.

You can also change the colour from the code.

Sub HighlightDuplicateValues

Dim myRange As Range

Dim myCell As Range

Set myRange = Selection

For Each myCell In myRange

If WorksheetFunction.CountIf(myRange, myCell.Value) > 1 Then

myCell.Interior.ColorIndex = 36

End If

Next myCell

End Sub

From < https://excelchamps.com/blog/useful-macro-codes-for-vba-newcomers/ >