Bob-
Any/all of those mentioned might get ya there. Likewise for leather dye, boiled onion skins or walnut hulls, hair dye or wood stain. Depends some on what yer after.
~Longshot
The commercially made product "Old Bones" (pot. perm.) works well, but very quickly...I've used RIT on buckskin, so I'd give it a try on the horn...probably take longer than the Old Bones which wouldn't be that bad a thing..Hank
I've used brown shoe paste on light horns and black shoe paste on green colored horns with great results. I'm experimenting with colored antique wood wax. So far the results haven't been encouraging.