Change cell color w/o using conditional formula

Adjust the range to the column and cell range you want "watched", then put this macro into the sheet module:

Sub worksheet_calculate()
Dim cell As Range, rng As Range
Set rng = Range("K5:K70")

For Each cell In rng
    If cell.Value = "Selfpay" Then
        With cell.Interior
            .ColorIndex = 3
            .Pattern = xlSolid
        End With
    Else
        cell.Interior.ColorIndex = xlNone
    End If
Next cell
End Sub