https://gonzodamus.github.io/FBV_Chroma/
Built this after going down the rabbit hole of trying to color-code my FBV3 for use with Gig Performer as a standalone MIDI controller.
Short version: the stock firmware just silently drops inbound MIDI over USB. This patch inserts a small CC handler and connects it to the LED routine that's already in the firmware.
The setup process is browser-based. You go to the web editor, click the "First time here" toggle, and then upload the original Line 6 firmware file. The site applies the patch locally in your browser and downloads the result. Then you flash it with the Line 6 Updater like any normal update. Firmware should then say FBV Chroma 1.1. After that the web editor (or any MIDI software) can control the LEDs directly. Reversible with a recovery boot + stock firmware.
You can save your preferred colors, set them to steady or blink, and invert the behavior of the LED (off when pressed, on when not pressed).
If you'd like to dig into the Github repo, you can check it out below. The only thing removed from the firmware is the factory manufacturing self-test (diagnostic routine). The LED handler lives in that dead space. Everything else MIDI out, the firmware updater, the LEDs themselves keeps working normally.
https://github.com/gonzodamus/FBV_Chroma
I've tested this on my PC and Mac and my FBV 3, and it works well for me. I'm a software engineer but firmware is new territory for me, so the usual caveats about running unofficial mods apply.
I'll do my best to answer any questions and respond to feedback :)
