I was just doing a little reading on HDRs and ran across a factoid about why there are pink (technically, salmon colored) and yellow versions.

The original HDR was yellow, and shortly after the invasion of Afghanistan started, the US started air dropping HDRs all over the place (actually, I remember seeing news reports of this). Unfortunately, unexploded cluster munitions are also yellow in color and there was a concern that people would inadvertently blow themselves up trying to collect these yellow-colored objects that had fallen from the sky. I mean, the cluster bombs were shaped like cans. How's an illiterate farmer supposed to know that it's not a can of beans or something? There were radio broadcasts warning the civilian population about the danger. I sure hope no one did get confused between the two.