I would probably keep the black one handy, if it makes you uncomfortable. I doubt the patrons at the wedding will be focused on the photographer’s strap.
I use a bright multicolored strap when I do children portraits. I usually reference my straps when I need them to look at the lens. Keeps parents from jingling keys in my ear. I wouldn’t personally use my pink sequin hand strap at a wedding, but for other events, I don’t see the problem.