I know its kind of late but I received the following
from Bill Laine from Wallingford Bikes when asked
about dye:
I think that the dye bleeding out of a saddle has a lot to do with how the saddle is treated.
If someone uses an oily leather treatment product like Neatsfoot
or Lexol the color is more likely to bleed out.
If someone puts on a _lot_ of Proofide with the expectation that
the saddle will get softer quicker then the color is more likely to bleed.
If you are conservative with your use of a wax-based leather
treatment, like Proofide, then color bleeding should be minimal.
Brooks says when you get a new saddle put on a heavy coat of
Proofide and wear your old shorts for the first few rides. After
that just use a little Proofide and the color should stay in the
saddle. (Normal Proofide use is a couple of fingernail scoops).
Marty