The learning part comes in when it comes to the colouring. As I wrote yesterday, I used FD&C blue; it morphed into pink. At least, it's pink on the outside. This morning, I cut it and received another surprise.
It's mauve! (See that gorgeous swirl? That makes me happy!) Some commenters on the SoapMaking forum have said it might not be finished morphing yet so it will be interesting to see what happens over the next six weeks or so.
As for lessons, I've learned that if I want a pretty mauve, I can use the FD&C blue. One poster on SMF said she uses this particular blue to make a royal purple colour. Another one suggested having a jar with pre-mixed lye water handy and using a sample cup of lye solution to test your colourant to see whether it will morph and if so, how it will change. What a great suggestion!