Excel VBA- Toggle row highlighting with each click of a macro - vba

Question

I have a macro that highlights a row if there is anything blank text in a specific column. This macro is used to highlight areas where a user needs to direct attention. I want to be able to unhighlight those rows after changes have been made, by clicking the same macro button.
How do I do this?
This is the current macro:
Sub Macro13()
With Application
CalcMode = .Calculation
.Calculation = xlCalculationManual
.ScreenUpdating = False
End With
With ActiveSheet
.Select
ViewMode = ActiveWindow.View
ActiveWindow.View = xlNormalView
.DisplayPageBreaks = False
Firstrow = 2
LastRow = .Cells(.Rows.Count, "M").End(xlUp).Row
For Lrow = LastRow To Firstrow Step -1
With .Cells(Lrow, "M")
If .Value = "" Then
.EntireRow.Interior.ColorIndex = 3
End If
End With
Next Lrow
End With
ActiveWindow.View = ViewMode
With Application
.ScreenUpdating = True
.Calculation = CalcMode
End With
End Sub
My idea was to, at the beginning of the macro, check to see if any row was highlighted red. If so, run a new loop that iterates through all columns, removing the cell highlighting, and then after that loop is done, break out of the macro. This is ugly and riddled with errors, though.
Sub Macro13() 'Checks for Incorrect Countries
With Application
CalcMode = .Calculation
.Calculation = xlCalculationManual
.ScreenUpdating = False
End With
With ActiveSheet
.Select
ViewMode = ActiveWindow.View
ActiveWindow.View = xlNormalView
.DisplayPageBreaks = False
Firstrow = 2
LastRow = .Cells(.Rows.Count, "M").End(xlUp).Row
FirstrowA = 2
LastRowA = .Cells(.Rows.Count, "M").End(xlUp).Row
For Lrow = LastRow To Firstrow Step -1
With .Cells(Lrow, "M")
If .EntireRow.Interior.ColorIndex = 3 Then
For LrowA = LastRowA To FirstrowA Step -1
.EntireRow.Interior.ColorIndex = xlColorIndexNone
Next LrowA
End
Exit Sub
End If
If .Value = "" Then
.EntireRow.Interior.ColorIndex = 3
End If
End With
Next Lrow
End With
ActiveWindow.View = ViewMode
With Application
.ScreenUpdating = True
.Calculation = CalcMode
End With
End Sub

Answer 1

This should do the trick for you. I've added a loop that looks for any formatting before it starts highlighting blanks. If if finds something red, it clears the whole sheet of red formatting and raises a flag (Tracker = True). When the flag is raised, the macro will not
format blank cells' rows as red. I tested it and it worked for me.
Sub Macro13()
With Application
CalcMode = .Calculation
.Calculation = xlCalculationManual
.ScreenUpdating = False
End With
With ActiveSheet
.Select
ViewMode = ActiveWindow.View
ActiveWindow.View = xlNormalView
.DisplayPageBreaks = False
Firstrow = 2
LastRow = .Cells(.Rows.Count, "M").End(xlUp).Row
Dim Tracker As Boolean
Tracker = False
For Lrow = LastRow To Firstrow Step -1
If .Cells(Lrow, "M").EntireRow.Interior.ColorIndex = 3 Then
.Cells.Interior.ColorIndex = 0
Tracker = True
Exit For
End If
Next Lrow
If Tracker = False Then
For Lrow = LastRow To Firstrow Step -1
With .Cells(Lrow, "M")
If .Value = "" Then
.EntireRow.Interior.ColorIndex = 3
End If
End With
Next Lrow
End If
End With
ActiveWindow.View = ViewMode
With Application
.ScreenUpdating = True
.Calculation = CalcMode
End With
End Sub

Answer 2

I've had a similar issue before and conditional formating didn't work well for me. I used something similar to this:
Sub CheckAndHighlight(area As Range, Optional ByVal searchValue As String = "")
Application.ScreenUpdating = False
Dim r As Range
For Each r In area
r.EntireRow.Interior.ColorIndex = 0
If r.Value = searchValue Then
r.EntireRow.Interior.ColorIndex = 3
End If
Next
Application.ScreenUpdating = True
End Sub