They’re worth playing around with. Back in 2016 I made a clip of Kylo Ren with a yellow lightsaber. I’d show it, but I must have taken it off of my youtube, and I know for sure I deleted it off of my computer. So it’s gone.
I prefer Kylo Ren with a red lightsaber, so I wouldn’t actually replace it, but it’s still cool seeing what could be. Anyway VFX for the sake of VFX isn’t a bad thing.