HUB75: Color Order setting is hidden in the UI, and only 2 of 6 orders are implemented

[jsenecal]

What happened?

For a HUB75 matrix bus, the LED Preferences page hides the "Color Order" dropdown entirely, even though the HUB75 driver in bus_manager.cpp reads and acts on that same value (it swaps GPIO pin roles to compensate for panels whose R/G/B lines aren't wired in the order WLED expects).

On top of that, only RGB and BGR are actually handled in firmware whilst the other four permutations (GRB, BRG, RBG, GBR) silently do nothing.

Root cause, wled00/data/settings_leds.htm:

gId("co"+n).style.display = (isVir(t) || isAna(t) || isHub75(t)) ? "none":"inline";       // hide color order for PWM

Per the comment, this was meant to hide the control only for PWM/analog/virtual buses; HUB75 appears bundled in by mistake.

Firmware side, wled00/bus_manager.cpp (BusHub75Matrix::BusHub75Matrix):

if (bc.colorOrder == COL_ORDER_RGB) {
    DEBUGBUS_PRINTLN("MatrixPanel_I2S_DMA = Default color order (RGB)");
} else if (bc.colorOrder == COL_ORDER_BGR) {
    ...swaps r1<->b1, r2<->b2...
} else {
    DEBUGBUS_PRINTF("MatrixPanel_I2S_DMA = unsupported color order %u\n", bc.colorOrder);
}
COL_ORDER_GRB (0, the system default for any new bus), BRG (2), RBG (3), GBR (5) all fall through as no-ops.

To Reproduce Bug

1. Add a HUB75 matrix bus in Settings -> LED Preferences.
2. Note there's no "Color Order" control for it (compare to a WS2812 bus on the same page).
3. Use a panel needing a non-RGB/BGR order (e.g. Green/Blue swapped); colors render wrong with no way to fix it in the UI.

Expected Behavior

Color Order dropdown visible for HUB75 buses; all 6 orders correctly remap R1/G1/B1/R2/G2/B2 GPIO roles.

Install Method

Self-Compiled

What version of WLED?

WLED 16.0.1 (2605010)

Which microcontroller/board are you seeing the problem on?

ESP32

Relevant log/trace output

Bus: Config (0-4096, type:65, CO:1, rev:0, skip:0, AW:0 kHz:0, mA:0/0, driver:RMT)
MatrixPanel_I2S_DMA = Default color order (RGB)

Anything else?

Suggested fix: drop isHub75(t) from the hide condition; extend the bus_manager.cpp chain to all 6 COL_ORDER_* values. Locally implemented/verified the RBG case. I'd be happy to open a PR with the full set. Hardware: classic ESP32 (no PSRAM), esp32dev_hub75 build env, 64x64 P2.5 panel with G/B swap.

Code of Conduct

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[DedeHai]

it is hidden intentionally as this feature is not (yet) implemented.

[softhack007]

Different to WS281x and friends, the HUB75 pinout clearly defines the color order, by assigning pins in the HUB75 plug to color components.

AFAIK the only "disorder" that has appeared in-the-wild is "BGR" - and that's most likely a defect in the panel internal wiring.
We should discuss if re-orderings other than "RGB" and "BGR" make sense.

[jsenecal]

RBG is what I got from my Aliexpress P2.5 64x64 panel, not sure if its a common occurence or not.

[netmindz]

Correct, colour order has no meaning in the world of hub75. In hub75 WLED if setting a pixel by pixel RGB value. The spec defines which pin is used for colour. There are however non complaint panels that have incorrect wiring for Hub75 so to support these, we need to swap pin rather than the ordering of which we sent the data

[jsenecal]

I understand but most adapter boards have a fixed pinout (like mine), one does not simply swap pins, unless you meant in software ?
My adapter board is wired for the default pinout of the ESP32-HUB75-MatrixPanel-DMA driver. So, technically, the display has the "wrong" colors.