Color Cell Based On Text Value

1. Copy the column you want to format to an empty worksheet.
2. Select the column, and then choose "Remove Duplicates" from the "Data Tools" panel on the "Data" tab of the ribbon.
3. To the right of your unique list of values or strings, make a unique list of numbers. For instance, if you have 6 categories to color, the second column could just be 1-6. This is your lookup table.
4. In a new column, use VLOOKUP to map the text string to the new color.
5. Apply conditional formatting based on the new numeric column.

The screenshots below are from Excel 2010, but should be the same for 2007.

Select the cell and go to Conditional Formatting | Highlight Cells Rules | Text that Contains

UPDATE: To apply the conditional formatting for the entire worksheet select all cells then apply the Conditional Formatting.

^{(Click image to enlarge)}

Now Just select whatever formatting you want.

From: http://www.mrexcel.com/forum/excel-questions/861678-highlighting-rows-random-colors-if-there-duplicates-one-column.html#post4185738

Sub ColourDuplicates()
Dim Rng As Range
Dim Cel As Range
Dim Cel2 As Range
Dim Colour As Long




Set Rng = Worksheets("Sheet1").Range("A1:A" & Range("A" & Rows.Count).End(xlUp).Row)
Rng.Interior.ColorIndex = xlNone
Colour = 6
For Each Cel In Rng


If WorksheetFunction.CountIf(Rng, Cel) > 1 And Cel.Interior.ColorIndex = xlNone Then
Set Cel2 = Rng.Find(Cel.Value, LookIn:=xlValues, LookAt:=xlWhole, MatchCase:=False, SearchDirection:=xlNext)
    If Not Cel2 Is Nothing Then
        Firstaddress = Cel2.Address
        Do
        Cel.Interior.ColorIndex = Colour
        Cel2.Interior.ColorIndex = Colour
            Set Cel2 = Rng.FindNext(Cel2)

        Loop While Firstaddress <> Cel2.Address
    End If




Colour = Colour + 1


End If
Next


End Sub