I am currently in the middle of attempting my first 4k render, so it'll be a bit, but I'll happily post my settings once this is done. My inner Star Wars geek got all excited when it came out looking as good as it did, lol.
Edit: Realized I forgot to turn on smoothing, so the render needed to stop anyway. *sigh*
Plus side, my settings:
Kernel and Imager
(Post processing settings may be adjusted, but this got the look I wanted for the glow effect, unsure if only works with this kernel, since I use it almost exclusively)
Mat settings
It looks horrible for the first few hundred samples, depending on scene, may take up to 20k+ samples to clear up
Final look
I stopped this at about 16k samples, as it was adequate for the render's purpose at the time, the image before went to about 35k, since it was a darker scene.
The alternate colors were variations of the diffuse RGB and Emissive RGB, generally in a similar ratio (I'd just shift the colors using the sliders).
This mat was set up in 1.2, but converts to 2.x just fine, since it's just a diffuse texture with RGB assignments.
I forget where I got the model for the saber, but it was a free pack of them uploaded somewhere. The blade itself looks like an orange plastic tube in the DS viewport.
Oh, the whole point of the experiment was to attempt to get a lightsaber effect
without post-work, so there is none on any of this, it's all straight from Daz and OcDS. Not that I dislike Photoshop, I was just curious how well Octane could manage unrealistic things, and it surprised me. Granted, Direct Lighting is technically biased, I still could not reproduce the effect in 3delight (despite trying for a few years).
...And now, back to restarting that 4k render attempt...