Coconut Milk Soap

[robotxnoise.livejournal.com]

I've recently gotten into soap making. I made a batch of coconut milk soap about two months ago, and it turned a dark pink color (it was originally very white), and so I threw it away. How long does soap usually last, and what kind of preservatives could I put into the next batch to help it not change colors or the coconut milk go bad?