The NASA DC-8 was up in the Pacific Northwest for the trials sampling the air when burning sustainable aviation fuel.  The aircraft that was actually burning the fuel that they were sniffing was a 737-10.  This Max 10 is ultimately destined for United Airlines.  Since the Max 10 is not certificated yet, I guess the jet was free for Boeing to use.  It had a special livery for the trials program.  Not sure whether this will be kept for service or not.  However, when I was shooting the DC-8, I usually got to shoot the Max as well.  It didn’t always get the best light, but I still got a few good shots of it.