Vanilla in a black and white soap.

[Purplerain]

If I use vanilla FO in the black part (activated charcoal) of a black and white swirled soap will it turn the black part brown and will it affect the white?

 

[TVivian]

The black will stay black. Whether the vanilla bleeds into the white depends on which vanilla you use. I've had vanillas that stayed only in the brown part and others which have completely overtaken any light colored swirls or stripes. It's really a trial and error thing I find.