mrjester, it is a silk knit, but the scale is finer than typical, so the sheen isn't as apparent.
I'm not sure how a grayscale fit calls for brown shoes. A knit tie may be more casual than a repp silk tie, but this one is black. Black shoes seems like an...uncontroversial choice. I would be more receptive to a call for black derbies.
I like what you have going on -- very minimal. I wonder if a black full brogue bal would be cool with it?