I don't think you can fix that. The AE bulb shines to a Celis tube (don't know how to call it exactly) that transfer the light to the AE rings. The yellow that you see might be a flaw in the Celis tube itself. Did you try to switch the bulbs and see what happen?
2000 Dinan S1 //M5 (my DD), 06 DINAN E53 4.8iS (wife's DD), 90 Straman Z32TT (my pride & joy ride)
Gone, but not forgotten: 01 E53 3.0i, 01 525i Sport, 03 DINAN 540i MSport and 91 Z32TwinTurbo