I've done it quite often. I use Kelly's Leather Dye on the leather after I've preped it with alcohol. It is no different then the way a shoemaker dyes shoes for a customer, but take your time with the prep.
The way I do it is to clean it several times with alcohol, let it dry over night. I'll then dye it with as many coats as necessary for the desired shade, then leave it alone for a day. Personally, I've never had the dye come off even after being soaked with water (I tend to ride through lakes, and in the rain) and repeated cleanings.