You obviously never had hids before!They emit a whiter beam than halogen!What colour is your beam?
Remove the inside back cover and check the fitment of the light,easy,it will either have a traditional bulb fitment or a hid round 2 pin....
Unfortunately on your X5 ,both hid and halogen headlights look similar,if you had an earlier X5 ,the low beam has a projector lens,the halogen has not !