@MasterOshawott-A touch of gold also works-he had both gold and silver integrated in his ZX costume.
What's the main theme of your AU? What things are different about it? That will effect his aesthetic. For instance, I'm also doing an AU, and in mine, I'm empathizing Zane's "clean slate" story and "lost" feel, so I put him in all plain white. If, say, I wanted his story in it to be more based on him being a leader, I'd give him details that make him stand out in a cool way and show confidence, etc.