Sub MyRandCharColors()
Dim oChr As Range
Dim sngRan As Single
Dim lngColorNext As Long
Dim wdOrange As Long
Dim varColors
wdOrange = 41215
varColors = Array(wdGreen, wdOrange, wdBlue)
Randomize
For Each oChr In Selection.Characters
  sngRan = Rnd()
  lngColorNext = varColors(Int((UBound(varColors) + 1) * sngRan))
  On Error Resume Next
  oChr.Font.ColorIndex = lngColorNext
  If Err.Number <> 0 Then
    oChr.Font.Color = lngColorNext
  End If
Next oChr
End Sub