Multiple condition, multiple range formating

This uses a Worksheet_Change macro to watch row 6 from D6 on. It uses an array of "steps" listed in a Select Case Value test.

All you need to do is enter the step #s in each Condition. After your original 3 samples, I added 3 more sets of random step selections to show the colors in action.

Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
'Format a range of cells based on drop selection
If Target.Count > 1 Then Exit Sub
If Not Intersect(Target, Range("C6:IV6")) Is Nothing Then
Dim i As Integer, v As Integer, c As Variant

i = Target.Column
v = 14  'add row variance
Range(Cells(15, i), Cells(45, i)).Interior.ColorIndex = xlNone

    Select Case Target.Value
        Case "Condition A"   'Orange
            For Each c In Array(1, 2, 7, 11, 15)   'Enter Step #s
                Range(Cells(c + v, i), Cells(c + v, i)).Interior.ColorIndex = 40
            Next c
        Case "Condition B"   'Lite Green
            For Each c In Array(2, 5, 9, 11, 16, 21, 25, 28, 30)
                Range(Cells(c + v, i), Cells(c + v, i)).Interior.ColorIndex = 35
            Next c
        Case "Condition C"   'Lite Blue
            For Each c In Array(1, 4, 9, 11, 16, 17, 18, 19, 22, 27, 30)
                Range(Cells(c + v, i), Cells(c + v, i)).Interior.ColorIndex = 37
            Next c
        Case "Condition D"   'Lavender
            For Each c In Array(3, 8, 9, 10, 12, 13, 19, 20, 24, 29)
                Range(Cells(c + v, i), Cells(c + v, i)).Interior.ColorIndex = 39
            Next c
        Case "Condition E"   'Pink
            For Each c In Array(6, 7, 8, 13, 14, 17, 19, 20, 23, 28, 31)
                Range(Cells(c + v, i), Cells(c + v, i)).Interior.ColorIndex = 38
            Next c
        Case "Condition F"   'Grey
            For Each c In Array(1, 10, 20, 30, 31)
                Range(Cells(c + v, i), Cells(c + v, i)).Interior.ColorIndex = 15
            Next c
        Case Else
    End Select
End If
End Sub