Just my 2 cents- But FYI- ION yellow- is good only if you are living where FOG is an issue while driving- or you are thinking that yellow looks Cool. Yellow is common in Europe,
because of the fog/rain/overcast- haziness- Yes- it does look good. But- You can do this another way-
Pay attention: Convert your high beam bulb to an H4 ( look at PIAA or HELLA brand)
with H4 base, You can buy the Yellow bulb and have your cake and eat it too- now choose 80-100 watt bulb to equation- But: be aware that extended use of high wattage may damage your lens ( mELt !!! ) . You will need to add a relay/harness to supply extra juice.. I did this conversion to my previous car a 94 probe gt..( but the headlight was ILLEGAL for use in usa ( non DOT approved ) but it was SICK bright.. 55 watt low beam, 130 watt high beams. It would toastrt the back of your neck if I was behind your car and flashed my brights.. HEH HEH.. ( those poor cabbies..slo mofos...) If I misunderstood the question- and you want BMW/Porsche type HID"s... you can apply same method, just use appropriate color bulb to the H4 setup. for the purplish/blue... again ..check out PIAA brand or HELLA catalog ( online..)