Ivory
Yeah, most ivory and mom-of-pearl grips are "presentation" grips not intended for shooting. They're veneers, you see.
I bought a pair of "Polymer ivory" grips from ajax for the colt officers pictured above. They looked like they had just been popped our of a plastic mold, so I sanded off all the sharpness and left longitudinal marks and a matte finish. Then I soaked them in coffee for a week. Now I've got them out in the sun to yellow.
They're starting to look more like ivory now. When I put them on, I'll post another picture. Have to get a new hat though. Gold tooth . . . .