Astronauts on Artemis II described more color variation(s) than simply dark grey. It is possible that the white balance was not set properly on the camera (which I doubt) but the image above (to me) shows a slightly warmer, almost brown hue that differs from the standard views of the moon that have been common thus far. It can be seen in the lunar flyby images in the NASA link below.
The warm hue is subtle but present.
https://www.nasa.gov/gallery/lunar-flyby/
"The astronauts reported some intriguing things, such as patches of green and brown on the lunar surface.
"We do know there is color on the lunar surface," Osinski said. The human eye, he added, is more sensitive to color than the cameras on board Artemis II, so "that's definitely going to be something interesting to follow up.""
https://www.livescience.com/space/t...cited-about-artemis-iis-historic-lunar-photos