T-H and LHG are about it. Paul's sun yellow has an orangy hue, and while Judy lists only the camo on her site, she might sell you some high HH in grey if you contact her.
Ray Jardine also sells sil, and has claimed that it has a superior HH. You might want to look at rayjardine.com and email them with an inquiry about purchasing sil with a high HH. In the past, they have sold red, and possibly orange also.
Extrem Textil, mentioned by Dustin, has a 55 gm sil that is listed at 3000mm, but it is green:
The reason I say that is about all there is, is becaue I spent several years searching for better quality silnylon during which Roger Caffin was kind enough to test a number of samples for me. What I found was that if the seller is not able to claim a specific high HH, the material is not that, no matter how well it is promoted, or suggested in these forums. A lot of time was wasted until I came to accept that. None of the many tests of sil kindly posted on this site by Richard Nisley gave me any reason to believe otherwise. Rather, they confirmed my own experience.
No question, the high HH material from Asia is available, but only in large quantities. So MYOGers are subject to what bulk purchasers have bought, and are willing to sell to us in small quantities.