Coloring Your Cold Process Soap

I would consider myself a beginner cold process soap maker.  I wanted to try a batch with a peppermint/vanilla scent to it.  With vanilla essential oil being so cost prohibitive and fragrance oil can make your batch turn brown.  So I was recommended by someone to use the Jack Frost fragrance oil from Nature's Garden, it will discolor. So I am on the hunt for titanium dioxide to make sure that when I swirl, that the white part stays as white as can be.  This is the confusing part. There are three types of Titanium Dioxide - Water, Oil and Methicone.  Not sure which one I should use for cold process soap. But I digress.  In my search I found this post from Great Cakes Soapworks on Coloring Your Cold Process Soap. So I found out how much I need to use but not exactly which one to use.  My search continues.