AI'm hoping to make a petal cake for my daughter's fourth birthday using the colors from Frozen. Does anyone know what Americolor gels I would use to achieve the different colors (blue, teal, purple, pink, green, etc.)? Thanks so much!

Does anyone have any suggestions? Thanks!

Here's the AmeriColor Color Chart.  Pretty much every color you mentioned they have as a color.   Have fun!
 

http://www.americolorcorp.com/colorchart.html

For the blue I use a tiny bit of royal blue to white frosting/fondant.  Sometimes I also add a drop of sky blue, but never just sky blue as it ends up looking too green.  I'm not sure about the Frozen specific shades of the other colors you mentioned, but I will say that I think the Americolor teal is very green with just a hint of blue when used straight, leaf green makes a pretty green, and I use the violet for most shades of purple, but the fuschia makes the perfect color for Anna's cloak.

Thank you!