Sub ListColorIndexes()
Dim Ndx As Long
Sheets.Add
For Ndx = 1 To 56
Cells(Ndx, 1).Interior.ColorIndex = Ndx
Cells(Ndx, 2).Value = Hex(ThisWorkbook.Colors(Ndx))
Cells(Ndx, 3).Value = Ndx
Next Ndx
End Sub
Also see David McRitchie's site for more on the color palette