多个移动对象，每个对象都附有文本

I've been playing with the interactive cubes and decided to add a click function, which leads to a specific link. Now I would like to add unique text on each block which is rendered as a material. For right now, I am using a single material, so I am thinking I need to create an array for all my possible materials, however whenever I reference that array in the parameters for building the mesh of my objects, I get a setHex() is undefined returned to me in the console. How can I attach a unique material to each cube? an