I emailed Satin Ice yesterday about coloring the fondant and this was their response:
If you go to our website we have a color mixing guide. It will show you how to make navy by mixing our colors together. We have two navys so you would need to decide.
One is~ 2 parts blue Satin Ice, 1 part pink Satin Ice and 1 part black Satin Ice. This is a vibrant navy.
We also have a muddled navy which is 6 parts blue and 1 part red.
It is really hard to achieve navy, black or red on your own using color gel. You can try adding Tylose or glycerin but I cannot guarantee results.
Good luckkeep me posted how it turns out." ~Satin Ice rep
Not much help regarding WHAT to do the fondant once color is achieved. I think I'll just buy navy Choco-Pan from here on... no point getting old coloring fondant!
Unless someone has a fool proof trick to get the fondant to go back to the proper consistency...