Dim cor() As Integer

Sub ki100()
  colb = Cells(11, 6).Font.ColorIndex
'
If IsNull(Cells(11, 6).Font.ColorIndex) = True Then
        s1 = Len(Cells(11, 6))
        ReDim cor(s1)
        Cells(11, 6).Select
    For i = 1 To s1
        cor(i) = ActiveCell.Characters(i, 1).Font.ColorIndex
    Next
        msg = ""
        For i = 1 To s1
           If cor(i) < 0 Then
              corno = "N"
           Else
              corno = cor(i)
           End If
           msg = msg & i & ":" & corno & ", "
        Next
        MsgBox msg
Else
       MsgBox "この文字列の一部に色が付いています"
End If
End Sub

Sub ki100a()
 colb = Cells(13, 6).Font.ColorIndex
'
If IsNull(Cells(13, 6).Font.ColorIndex) = True Then
   MsgBox "この文字列の一部に色が付いています"
Else
   MsgBox "この文字のColorIndex番号は：" & colb
End If
End Sub