I came across an article about an upscale bar in Des Moines that instituted a dress code: no baggy jeans, no T-shirts, no construction boots. Yes, this was called racist even though it was applied to everybody. From what I could understand from the muddled comments is that the reason it is racist is that minorities like to wear those clothes, no matter that many non-minorities do likewise.
I myself never equated work boots with minorites. I always thought they were more the Nike types.
Dazzling urbanites with work boots? Must be a very small regional thing, as I suspect the "red shoelaces" thing started out. SPLC has a talent for sniffing out "hate groups" that have around five members.