Considere:
Sub ColorMeRed()
Dim r As Range, v As String, L As Long
Dim RedMe As Boolean, i As Long
For Each r In ActiveSheet.UsedRange
v = r.Text
If InStr(v, "[") > 0 Then
L = Len(v)
RedMe = False
For i = 1 To L
If r.Characters(i, 1).Text = "[" Then
RedMe = True
ElseIf r.Characters(i, 1).Text = "]" Then
RedMe = False
Else
If RedMe Then r.Characters(i, 1).Font.Color = vbRed
End If
Next i
End If
Next r
End Sub
Por exemplo: