Formula's can't colour cells, so we have to use VBA.
The way the code below works is that whenever you make a change to your table of values, the formula in column O will recalculate. This will trigger the code. The only thing you have to keep in mind is to use the enter or arrow down keys to confirm your entry for the code to work as it is designed. The value in column N is then looked up in row 4 of columns A to L. Finally the colours are matched.
Here is the code:
Private Sub Worksheet_Calculate()
Dim fCell, dCell As Range
Set dCell = Range("N" & ActiveCell.Row).Offset(-1, 0)
Set fCell = Range("A4:L4").Find(dCell.Value)
Application.CutCopyMode = False
To implement the code, right-click your sheets tab and select view code, then paste the code above in the big white field.
Is this a good solution for you?