It might be worthwhile to shoot them on the Daylight setting. I've done a few beamshots in the past using Daylight because I wanted a single setting that would allow me to compare beam colors across different kinds of lights. Using Daylight, incandescents appear warmer and LED's cooler, but that's pretty much what the eye sees too. I think Auto would try to correct beam color differences to make them look more like what you would see in day lighting. I guess that's OK too if that's what you want. For example, I shot these on the Daylight setting.
The CMG Reactor 3 in real life looks whiter, but shooting all 3 photos on the Daylight setting illustrated the different beam colors.
Phil