Mike I don't know about saddle soap.
I am a bartender and often wear black leather vest. After a while they get dirty and pass off black stains to my white shirts, the leather cleaning guy says he does some sort of magical "dry cleaning" thing to them for the amazing low price of $75!
He won't elaborate on the process and I won't part with my $75 so what I do is every couple of weeks is get a wet, warm rag and scrub my leather. I don't get it soaking wet or anything. This seems to work for me and the leather and color holds up quite well.