Sometimes it takes over night for the dye to finish moving through the leather. Oiling it after you dye it also helps the dye to even out , also let the oil sit over night before you judge it. I use Angelus alcohol based dyes and apply with a wool dauber. Do you apply the dye in lines or in random circles? I’ve had better luck getting down into things and mor even coverage using circles. Leather quality dose make a difference also. I’m not to the point where I think I’m ready to buy good leather yet so I get some of those spot that don’t take dye real well it’s part of it. Just keep after it and it will get better.