Thank you for this!
Perhaps settings for customization might be an option?

What customization do you have in mind?

Radius and intensity of the flashlight and perhaps, what color.

I have one grander idea:
Compatibility with https://mods.factorio.com/mod/NightvisionOverhaulSpaceAge
When nightvision MK-1 is equiped you have the light as that nightvision, same for MK2 and MK3

The radius and intensity is hardcoded by the game engine. If you want it customizable you'll have to make a feature request for it on the forums.

As for changing it based on equipment, that's not really possible. All you can do is turn it on or off, and only while in remote view. It doesn't work for the regular character view.