I found this. Not exactly what you are looking for, but might get your started.
Sub ColourCells()
Dim rngLook, rngC As Range
Dim i As Integer
Dim strNew As String
Set rngLook = Range("F21:F25")
For Each rngC In rngLook
If Left(rngC, 1) <> "=" And Len(rngC) > 0 Then
For i = 1 To Len(rngC)
Debug.Print Mid(rngC, i, 1) & " colour " & rngC.Characters(i, 1).Font.Color
Select Case Mid(rngC, i, 1) & rngC.Characters(i, 1).Font.Color
Case "G0"
strNew = strNew & "G"
Case "G255"
strNew = strNew & "g"
Case "G4626167"
strNew = strNew & "Gf"
Case "G65535"
strNew = strNew & "Gm"
End Select
Next i
rngC.Value = strNew
rngC.Font.Color = 0
End If
Next rngC
End Sub