night vision in OB made me want to puke I was sick of that blue light, its not the 20th century its magic, it does not need to be blue.
Human eyesight is most sensitive to light with a wavelength of 540 nm (slightly lime green). This is why night vision goggles use this spectrum (not because of technical limitations) but because they only have to augment the image a little to give the user enhanced perception in low light circumstances.
It's simply the most effective, and this would be applicable to magic too. The "lime green" is not high-tech, it's basic science being put to effective use.
Night vision goggles could use red light instead of green, but that would be a silly way to design them. Because by doing so,
you elevate noise levels and
greatly increase the contrast between light sources and what's in the darkness (which can lead to blindness and is already a problem with green NV).
Lime green is the best night vision, whether it's technology or magic or a trick a little bird told you.