I'd rather keep this to the Brimstone lasers, but if you want to make an add-on of sorts, here's you you can do it (somewhat copy/pasted from another discussion):

What you're gonna want to do is make a folder in your mods folder named whatever you want your mod to be named (in my case, "Dogma Lasers").
In order to modify a specific sprite, you need to copy the file path from how it appears when extracted (if you haven't extracted files for modding, here's a tutorial for that: https://moddingofisaac.com/help/abplus/). For example, the standard brimstone graphics are located under resources/gfx/effects/ so you need to make folders within your mod folder that go resources > gfx > effects.
After that, add your custom .png file with the same file name you want to modify within the innermost folder. In order to replace "effect_018_lasereffects" (standard Brimstone), your .png needs to be named "effect_018_lasereffects"
Replace all of the png files you want to modify, and you're good to go!

With changing the Revelation laser specifically, it's found under effect_018_lasereffects, on the right-most part of the sprite. Modifying that spritesheet will also modify every other laser on it, so be wary of that; if you wanna keep the other Dogma laser, use my spritesheet as a base.

For sprite modification, I use Piskel. The way I created the static for the effect is by creating a "mold" in the shape of the laser by filling in the sides around the base asset, pasting the static asset used for the Clicker (I believe it's under UI somewhere) on another layer, pasting that mold over the static layer, then deleting the mold. That way, you're just left with the static in the shape of the laser. I'd suggest also making some white semi-transparent layers on top of the static to mimic the light effect so it isn't just a big block