RGB channels incorrect even with HyperHDR color test (WLED + direct GPIO both affected)

[DelMarvelous]

Hi all,

I’m looking for a sanity check before replacing hardware.

Setup
• HyperHDR (latest)
• Raspberry Pi 3
• USB HDMI capture device (UVC)
• LEDs confirmed good
• Tested both:
• Output to WLED
• Direct GPIO output from the Pi (no WLED in path)
• HDMI source includes streaming content (Netflix/Hulu, 4K HDR to TV)
• Clean config: no LUTs, no auto calibration

Issue
• Even using HyperHDR’s built-in color test / solid colors, I cannot get RGB to line up correctly:
• Selecting Blue shows as Green
• Other colors are similarly shifted
• I have tried all RGB/GRB/BRG/etc. orders with no combination producing correct RGB.
• White appears correct.

Important confirmations
• When driving the LEDs directly from WLED standalone, RGB colors are correct.
• When bypassing WLED and using direct LED output from the Pi, the same incorrect colors appear.
• HyperHDR Live Capture preview already shows incorrect colors compared to the TV image.

Conclusion so far
• This seems to point to a capture / colorspace / YUV→RGB interpretation issue upstream of LED output, not WLED, wiring, or LED hardware.
• I’m trying to confirm whether this behavior is known with certain USB grabbers (especially with HDR sources), or if there’s a HyperHDR setting I may be missing.

Any confirmation before I switch to an SDR-only grabber + splitter would be appreciated.

[awawa-dev]

https://forums.raspberrypi.com/viewtopic.php?t=361116&start=150