Question, how much wood could a woodpecker peck if a woodpecker could peck wood? Answer: quite a bite actually. Male Red-bellied Woodpecker digging out a nest at Wakodahatchee.
I shot this with my Sony 600mm f4 @ f4 at the minimum focusing distance because the woodpecker was so close. I knew my depth of focus was going to be limited but I also wanted the background blurred and the wood chips sharp. I shot at a very high shutter speed to catch the wood chips as they flew so I shot at 1/5000 sec. iso 8000, hand held, aperture priority -1 EV. I shot many shots as the woodpecker brought out his head and wiped the wood chips from his beak. The shot was further worked on in Photoshop and topaz AI.
I got lucky on this one.
Enjoy and keep on shooting until the end.

That is correct. At the same light intensity, red is better because it has least impact on the rods in your eyes. However, if you are trying to see details, then there is the tendency to use higher intensity red, and that impacts night vision. Green is better for details, and that is why green is used in night vision goggles.

So the answer is that red is best as long as the intensity is low, but if you need to see details, then using a higher intensity red versus a lower intensity green is not good.

You have received a lot of conflicting answers here. Some have a glimmer of truth. Some are based on limitations of early technology. Most have nothing to do with your question concerning night photography. For instance...night vision scopes had green displays because the early versions used an excited phosphor display. The phosphor used glowed green when excited. Same reason almost every early oscilloscope had a green CRT display.

One reason for concern with night displays is keeping the bad guy from seeing you. Any monochromatic color is helpful with this. Since a surprisingly high percentage of the population is red/green color blind, either of those colors can work at low intensities Green can be pretty good outside in green foliage. Blue is actually a poor choice, because many people cannot see very well in blue light that is close to monochromatic and is really blue. Compensation via increasing the intensity by a lot is frequently required.

A second concern around night vision is not messing up the vision of the other folks on your own team. For night photography, keeping the peace will require you to have a red light. No one is going to care about a discussion of green or blue as an alternative. A red light will avoid banishment to the wilderness.

Finally, you want to preserve your own vision. Biologically, the color you want is red. Red is the only color that will avoid chemically killing your night vision for 15-20 minutes. Ideally, you are going to be working in an environment of total darkness (or as close to it that the difference doesn't matter). And you will find that there is a big difference between this kind of darkness and the more commonly experienced darkness. (As we learned in The Princess Bride, there is a big difference between mostly dark and all dark.)

So...red is the color.