We passed this one over to Denny, our master craftsman.
You are using a great method to color your leather and define your tooling, but you may want to reconsider your materials if you would like to avoid muddiness. Like the generic name suggests, the tan kote and resolene will resist the antique, but it will not prevent it from doing its job. That means that no matter how much you apply, there will still be some darkening. If at all possible, the only thing you would be able to do with those materials is to be extremely, maybe even impossibly, careful about the application. Otherwise, considering other coloring options like paint or protective options like tape may be your solution.