Sigh.. Well.
I started trying out this dye on a bone colored Soho #4156. The leather is in better condition than what the Willis was. I dunked, cleaned and deglazed prior to dyeing. Same process as before. I didn't want to go too dark so I used less dye. Better to be too light because you can redunk. The color I was looking to achieve was "elephant gray".. For some reason, the color did not adhere well. I don't know why yet. I'm going to contact the company and inquire and see if maybe I need more dye for lighter leathers or if there's a different process.
In the meantime, if anyone has light colored bags and is considering this process, I think there's more involved with the lighter leathers. I'm not sure yet. I will update!