Varuscelli, that's news to me. Any of the H51 threads since they've been out, I've failed to even notice the GITD holders, and I normally see only the black ones. Anyone have a picture?
I can't actually speak to the question about the H51 headlamps by ownership (that is, I've never received an H51 package in the mail from ZL), but when I look on the ZebraLight page for any given light, I can scroll down to the section that's labeled "Accessories in the Package" and it looks as though all the AA headlamps show as including the GITD holder. I'm kind of speculating here, but maybe most folks show pics of their headlamps in the headband holders and I think the holders that come attached to the headband are perhaps always the black ones with the GITD ones as loose accessories.
As a kind of interesting side note, I wanted to order a couple of extra GITD and black holders from ZebraLight to experiment with, and when I did so the black ones they sent me came attached to headbands. So, I got headbands with both the black ones (when I thought I would be getting loose black holders) and the GITD holders were loose in the package. But ZL also sent me a GITD on a lanyard, an extra pocket clip, and some extra o-rings. Considering all I wanted were two extra black holders and two GITD holders to experiment with, they sent me a BUNCH of extra stuff at no extra cost (two extra headbands, an extra GITD holder on a lanyard, an extra pocket clip and extra o-rings).
Here's a pic of the package of goodies I received when I ordered two black holders and two GITD holders: