I found a similar solution to this question in c# How to Select all the cells in a worksheet in Excel.Range object of c#?
What is the process to do this in VBA?
Here is what I used, I know it could use some perfecting, but I think it will help others...
''STYLING''
Dim sheet As Range
' Find Number of rows used
Dim Final As Variant
Final = Range("A1").End(xlDown).Row
' Find Last Column
Dim lCol As Long
lCol = Cells(1, Columns.Count).End(xlToLeft).Column
Set sheet = ActiveWorkbook.ActiveSheet.Range("A" & Final & "", Cells(1, lCol ))
With sheet
.Interior.ColorIndex = 1
End With