I would try adding code like this to your form. I used the colors as the values, but you can update accordingly
(and update the control name, of course!).
Private Sub Combo0_Change()
With Me.Combo0
Select Case .Value
Case "Green": .BackColor = vbGreen: .ForeColor = vbBlack
Case "Yellow": .BackColor = vbYellow: .ForeColor = vbBlack
Case "Orange": .BackColor = 33023: .ForeColor = vbBlack
Case "Red": .BackColor = vbRed: .ForeColor = vbBlack
Case "Black": .BackColor = vbBlack: .ForeColor = vbWhite
Case "Grey": .BackColor = 8421504: .ForeColor = vbBlack
Case Else: .BackColor = vbWhite: .ForeColor = vbBlack
End Select
End With
End Sub