Excel VBA - Financial Model Color Formatting - excel

Question

In financial models it is common to colour-code the cells based on their input (see here for example). I would like to create a macro that automates this task for me.
The required colour-code is the following
Blue: Constants (except text)
Black: Formulas
Green: References to other sheets
Red: References to separate files or external links
Thanks to the great answers of Rory and Samuel I was able to achieve the above with the following code:
Sub financial_color_coding()
' Color hard-coded cells blue
With Selection.SpecialCells(xlCellTypeConstants, 21).Font
.Color = -65536 ' colour selected cells blue
.TintAndShade = 0
End With
' Select cells that contain formulas
Selection.SpecialCells(xlCellTypeFormulas, 23).Select
'Color selected cells based on their input
For Each cell In Selection
If Left(cell.Formula & " ", 1) = "=" Then
If InStr(CleanStr(cell.Formula), "]") Then
cell.Font.Color = RGB(255, 0, 0) ' red for references to other files
ElseIf InStr(CleanStr(cell.Formula), "!") Then
cell.Font.Color = RGB(0, 150, 0) ' green for references to other sheets
Else
cell.Font.Color = RGB(0, 0, 0) 'black for every other formula
End If
End If
Next cell
End Sub
Function CleanStr(strIn As String) As String
Dim objRegex As Object
Set objRegex = CreateObject("vbscript.regexp")
With objRegex
.Pattern = "\""[^)]*\"""
.Global = True
CleanStr = .Replace(strIn, vbNullString)
End With
End Function
Running the marco will only change the font of cells in a workbook that contain either a constant number or a formula and will keep the overall formatting of the text unchanged.

Answer 1

SpecialCells are documented here:
https://learn.microsoft.com/en-us/office/vba/api/excel.range.specialcells
However, not all can be done with it. If a formula contains a ! or ] it references to another sheet or file. The CleanStr removes all text in quotes, since these text may also include these characters.
Selection.SpecialCells(xlCellTypeConstants).Font.Color = RGB(0, 0, 255) 'blue for constant
Selection.SpecialCells(xlCellTypeFormulas).Font.Color = RGB(0, 0, 0) 'black for formulas
'to be more specifiy
For Each cell In Selection
If Left(cell.Formula & " ", 1) = "=" Then
If InStr(CleanStr(cell.Formula), "]") Then
cell.Font.Color = RGB(255, 0, 0) ' red for references to other files
ElseIf InStr(CleanStr(cell.Formula), "!") Then
cell.Font.Color = RGB(0, 150, 0) ' green for references to other sheets
Else
cell.Font.Color = RGB(250, 0, 255) 'pink for formulars with output text
End If
ElseIf Not IsNumeric(cell.Text) Then
cell.Font.Color = RGB(0, 0, 0) 'black for text constant
End If
Next cell
The CleanStr is adopted from here: Remove text that is between two specific characters of a string
Function CleanStr(strIn As String) As String
Dim objRegex As Object
Set objRegex = CreateObject("vbscript.regexp")
With objRegex
.Pattern = "\""[^)]*\"""
.Global = True
CleanStr = .Replace(strIn, vbNullString)
End With
End Function