Ive tried fitting many led type combos and all resulted in fantastic white light which matched my headlights but none seem to light the halo fully and it was hard in general distinguishing the halo when the headlights were on - as documented by many people on the forum.
I reverted back to the stock sidelight bulbs and I now quite like the yellowish light as theres a nice contrast between the halo and headlight making it always visible as well as the halo always being fully lit.
I then decided to fit some more powerful 10w 503 style bulbs which are the same length in total and same connection as the stock 501s so sit in the same positon in the light housing. This has resulted in a much more brighter halo - great success (borat). And the contrast is great. I would love a set of ccfls like cj10jeeper but I aint got the balls to pull my light apart so this is the best alternative imo. Just my 2 pence.
I fitted some 5-led bulbs. They look great, the only problem is they are a little blue-ish compared to my standard Halogen headlight bulbs. Could somebody give me a good H7 option, with a blue tinge? Osram/Phillips?