You can buy the OEM European headlight housings without the amber from any dealer, but it'll cost a lot.. like a grand..
There's also a couple other options such as body painted headlight reflector covers:
http://www.bimmian.com/82/HRC/
Or Vitex Ambergone vinyl overlays:
http://www.**********s.com/_e/E82_Ex...2_E87_E88_.htm