I would contact Guts Racing or have Go Fasters do it to see what they can do for you. I also really like a nice 2/3 tone seat cover over straight black.
They have nice two tone seats for almost every make including Beta, Husky, Husaberg etc. Of COURSE the GG page is freaking blank! You know they could build you up a tall seat in red/black but it might take GF to twist their arm.
Look here for the nice 2 tone Beta seat. I mean WTF, GG sells more bike than Beta I'm sure but as usual we get second fiddle.
Blackbird Racing in Europe (Italy I think) makes some sick GG packages. Not sure if they have or you could get em to do a tall seat cover. Really nice covers but I think you have to buy the entire graphics package to get the covers.