Illuminating a scene with a flashlight

Hello everyone. My project includes several (and by several I mean a big bunch of) scenes where everything is pretty much at night and the character is aiming a flashlight wielding towards the background, which changes its colours when receives its light (allegedly shows its true colours), but only on the spot where the flashlight is at the moment, which will be obviously a moving path/spot.

I really don’t know if there’s a filter or something in the library I can use. Since I remember in another project whit a transition from night to day I had to paint a second background with the day pallet.

Any guidance or advice is appreciated. Thanks.

Hey there, if you are looking for a nice tutorial you should check out this video (there are entire series on how to begin and improve).
https://www.youtube.com/watch?v=MI65MRdKfIY
If you are looking for more help i recommend you to take a look at custom research papers.