Our opinion about the dress code for a videographer at a wedding is this: we are next to the newlyweds and guests and should look neat and strict, but not stand out (after all, we should not be the center of attention).
Our appearance is something like this: black trousers and a black (sometimes white, depending on the event) shirt. In black, we are not so noticeable in the reflections of the objects being shot (glasses, mirrors), and if we suddenly get somewhere in the frame to the photographer at a reporting moment, most likely no one will even notice us.