Color the sequence of letters from column B to column A !

GEEK_21 

Run this macro:

Sub ColorLetters()
    Dim rng1 As Range
    Dim rng2 As Range
    Dim cel1 As Range
    Dim cel2 As Range
    Dim val1 As String
    Dim val2 As String
    Dim n As Long
    Dim pos As Long
    Application.ScreenUpdating = False
    Set rng1 = Range(Range("A1"), Range("A" & Rows.Count).End(xlUp))
    rng1.Font.ColorIndex = xlColorIndexAutomatic
    Set rng2 = Range(Range("B1"), Range("B" & Rows.Count).End(xlUp))
    For Each cel1 In rng1
        val1 = cel1.Value
        If val1 <> "" Then
            For Each cel2 In rng2
                val2 = cel2.Value
                If val2 <> "" Then
                    n = Len(val2)
                    pos = 0
                    Do
                        pos = InStr(pos + 1, val1, val2, vbTextCompare)
                        If pos = 0 Then Exit Do
                        cel1.Characters(Start:=pos, Length:=n).Font.Color = vbRed
                    Loop
                End If
            Next cel2
        End If
    Next cel1
    Application.ScreenUpdating = True
End Sub