Try this small macro:
Sub altan()
n = Cells(Rows.Count, "A").End(xlUp).Row
v1 = 1
v2 = 56
Set r = Range("A:A")
For i = 1 To n
Set r2 = Cells(i, 1)
m = Application.WorksheetFunction.CountIf(r, r2)
If m > 1 Then
p = Int(((v2 - v1 + 1) * Rnd) + v1)
Cells(i, 1).EntireRow.Interior.ColorIndex = p
End If
Next
End Sub

Signature
Gary''s Student - gsnu200787
> Visual Basic 6.3/Excel 2003/XP
>
[quoted text clipped - 31 lines]
>
> -Altan