I also had this problem last year and I called Lexus multiple times until they paid for me to get my headlights replaced at the dealership because my warranty had just expired try calling and see if you make any progress
I got some blue LEDs on eBay for about $12 they look great.
http://i1085.photobucket.com/albums/j425/trey8481/Mobile%20Uploads/9D4A0568-09C9-44EF-8D34-F04C793F0105.jpg