Here is something to add. I have a hide from Tandy that just won't evenly take diluted dye of any mixture.
I was using fiebings mahogany. It continued to come out putrid variations of purple with darker specs all over it.
I had this same result with daubers, sponges, and dip dyeing. I finally had to resort to full strength.
This left me with a black piece with a hint of purple.
So, take note of the leather you are using. Cheap leather can leave you blaming the dye or technique, when you should really be addressing the material.
Just a heads up.