In this occasionally interesting but, as is customary, error-strewn doco, there's a strange moment after 18'00".
"The American forces, which had begun arriving in France in summer 1917, soon replaced their French helmets with the British version," says the narrator (who appears to be Robert Powell, and who can't pronounce 'Cambrai'). There's a short clip of US troops marching and, indeed, wearing what look like Adrians. The men are white, so it's not a Colored Regiment. It might even be Gen. Pershing at the head of the column.
"Sometimes things that are not true are included in Wikipedia. While at first glance that may appear like a very great problem for Wikipedia, in reality is it not. In fact, it's a good thing." - Wikipedia.
Not been able to find anything official though, possibly issued to some servicemen not directly in the front line with the exception of the Colored US units fighting with the French.