Randomizing Material Selection for DirectShape

Hello,

I am attempting to randomize the material selection of some banners that are being generated by the DirectShape.ByGeometry node. I have generated these by selecting the edges of the geometry that will serve as the boundary, once those are subdivided I have connected them to generate the second boundary. I then subdivided those segments and connected them with an arc to generate an extruded surface which I then thickened to get a solid.

Once I have this solid I want to assign a material to it so that I can have Red, Yellow and Orange banners that create some type of visual pattern. I attempted to do so by getting the materials from various objects in Revit and then creating a list of the various materials to input into the DirectShape node however when I do so only the first line of banners is colored with only 1 color. I have tried Shuffling the list as well as List.Cycle and nothing seems to work.

Anyone know what I am doing wrong? Thanks for all the help!

Dynamo File: