Hello,
I doubt that anyone can tell you whether it is ivory or not based on the photos you provided and considering the condition of the hilt where just tiny spots of the base material are exposed.
However, the colour of the exposed areas seem to be consistent with antique elephant ivory.
Please keep it in mind that at the time this hilt was made, ivory was not subject to so many restriction like now and it was quite available (albeit it was always on the expensive side).
Now, why is the hilt so dark, I have no idea but it might be that is simply dirty or maybe it was painted?!
However, I am just a novice when it comes to kerises.
