I used Exit For as suggested in Excel VBA - exit for loop to fix the overwrite. I am getting Next without For error on Next j line, which is the second line to the end.
For i = 2 To lastrow
For j = 99 To 167 Step 6
If (Not IsEmpty(ActiveSheet.Cells(i, j)) And Not IsEmpty(Cells(i, j + 2))) Then
Cells(i, 2).Interior.Color = vbRed
Cells(i, 3).Interior.Color = vbRed
Exit For
If (Not IsEmpty(ActiveSheet.Cells(i, j)) And Not IsEmpty(Cells(i, j + 8))) Then
Cells(i, 2).Interior.Color = RGB(146, 208, 80)
Cells(i, 3).Interior.Color = RGB(146, 208, 80)
Exit For
If (Not IsEmpty(ActiveSheet.Cells(i, j)) And Not IsEmpty(Cells(i, j + 14))) Or _
(Not IsEmpty(ActiveSheet.Cells(i, j)) And Not IsEmpty(Cells(i, j + 20))) Then
Cells(i, 2).Interior.Color = vbYellow
Cells(i, 3).Interior.Color = vbYellow
Exit For
Next j
Next i